trying to access object property makes it empty - javascript [duplicate] - javascript

Below, you can see the output from these two logs. The first clearly shows the full object with the property I'm trying to access, but on the very next line of code, I can't access it with config.col_id_3 (see the "undefined" in the screenshot?). Can anyone explain this? I can get access to every other property except field_id_4 as well.
console.log(config);
console.log(config.col_id_3);
This is what these lines print in Console

The output of console.log(anObject) is misleading; the state of the object displayed is only resolved when you expand the Object tree displayed in the console, by clicking on >. It is not the state of the object when you console.log'd the object.
Instead, try console.log(Object.keys(config)), or even console.log(JSON.stringify(config)) and you will see the keys, or the state of the object at the time you called console.log.
You will (usually) find the keys are being added after your console.log call.

I've just had this issue with a document loaded from MongoDB using Mongoose.
When running console.log() on the whole object, all the document fields (as stored in the db) would show up. However some individual property accessors would return undefined, when others (including _id) worked fine.
Turned out that property accessors only works for those fields specified in my mongoose.Schema(...) definition, whereas console.log() and JSON.stringify() returns all fields stored in the db.
Solution (if you're using Mongoose): make sure all your db fields are defined in mongoose.Schema(...).

Check if inside the object there's an array of objects. I had a similar issue with a JSON:
"terms": {
"category": [
{
"ID": 4,
"name": "Cirugia",
"slug": "cirugia",
"description": "",
"taxonomy": "category",
"parent": null,
"count": 68,
"link": "http://distritocuatro.mx/enarm/category/cirugia/"
}
]
}
I tried to access the 'name' key from 'category' and I got the undefined error, because I was using:
var_name = obj_array.terms.category.name
Then I realised it has got square brackets, that means that it has an array of objects inside the category key, because it can have more than one category object. So, in order to get the 'name' key I used this:
var_name = obj_array.terms.category[0].name
And That does the trick.
Maybe it's too late for this answer, but I hope someone with the same problem will find this as I did before finding the Solution :)

I had the same issue. Solution for me was using the stringified output as input to parsing the JSON. this worked for me. hope its useful to you
var x =JSON.parse(JSON.stringify(obj));
console.log(x.property_actually_now_defined);

The property you're trying to access might not exist yet. Console.log works because it executes after a small delay, but that isn't the case for the rest of your code. Try this:
var a = config.col_id_3; //undefined
setTimeout(function()
{
var a = config.col_id_3; //voila!
}, 100);

In my case I was passing an object to a promise, within the promise I was adding more key/values to the object and when it was done the promise returned the object.
However, a slight over look on my part, the promise was returning the object before it was fully finished...thus the rest of my code was trying to process the updated object and the data wasn't yet there. But like above, in the console, I saw the object fully updated but wasn't able to access the keys - they were coming back undefined. Until I saw this:
console.log(obj) ;
console.log(obj.newKey1) ;
// returned in console
> Object { origKey1: "blah", origKey2: "blah blah"} [i]
origKey1: "blah"
origKey2: "blah blah"
newKey1: "this info"
newKey2: "that info"
newKey3: " more info"
> *undefined*
The [i] is a little icon, when I hovered over it it said Object value at left was snapshotted when logged, value below was evaluated just now. Thats when it occurred to me that my object was being evaluated before the promise had fully updated it.

I just encountered this issue with objects generated by csv-parser from a CSV file that was generated by MS Excel. I was able to access all properties except the first property - but it would show up ok if I wrote the whole object using console.log.
Turned out that the UTF-8 CSV format inserts 3 bytes (ef bb bf) at the start corresponding to an invisible character - which were being included as part of the first property header by csv-parser. Solution was to re-generate the CSV using the non-UTF option and this eliminated the invisible character.

I struggled with this issue today, and thought I'll leave a reply with my solution.
I was fetching a data object via ajax, something like this:
{"constants": {"value1":"x","value2":"y"},"i18n" {"data1":"x", "data2":"y"}}
Let's say this object is in a variable called data. Whenever I referenced data.i18n I got undefined.
console.log(data) showed the object as expected
console.log(Object.keys(data)) said ["constants","i18n"] as expected
Renaming i18n to inter didn't change anything
I even tried to switch the data to make "i18n" the first object
Moved code around to make absolutely sure the object was completely set and there was no problem with the ajax promise.
Nothing helped... Then on the server side I wrote the data to the php log, and it revealed this:
{"constants": {"value1":"x","value2":"y"},"\u045618n" {"data1":"x", "data2":"y"}}
The "i" in the index key was actually a u0456 (cyrillic i). This was not visible in my php editor or the browser console log. Only the php log revealed this... That was a tricky one...

My data was just json data string . (This variable was stored as json string in the session).
console.log(json_string_object)
-> returns just the representation of this string and there is no way to make difference whether is string or object.
So to make it work I just needed to convert it back to real object:
object = JSON.parse(json_string_object);

In 2018 Mozilla warns us in the Mozilla Docs here!
I quote "Logging Objects":
Don't use console.log(obj);,
use console.log(JSON.parse(JSON.stringify(obj)));.
This way you are sure you are seeing the value of obj at the moment
you log it.

If this is an issue occurring when working with Mongoose, the following may happen:
console.log(object)
returns everything, including the desired key.
console.log(object.key)
returns undefined.
If that is happening, it means that the key is missing from the Mongoose Schema. Adding it in will resolve the issue.

For me it turned out to be a Mongoose-related problem.
I was looping over objects that I got from a Mongo query. I just had to remove:
items = await Model.find()
And replace it by:
items = await Model.find().lean()

This might help somebody as I had a similar issue in which the JSON.parse() was returning an object that I could print on the console.log() but I couldn't acccess the specific fields and none of the above solution worked for me. Like using the combination of JSON.parse() with JSON.stringify().
var jsonObj = JSON.parse(JSON.stringify(responseText))
// where responseText is a JSON String returned by the server.
console.log(jsonObj) ///Was printing the object correctly
console.log(jsonObj.Body) /// Was printing Undefined
I ended up solving the problem by using a different parser provided by ExtJs Ext.decode();
var jsonObj = Ext.decode(responseText)
console.log(jsonObj.Body) //Worked...

I had the same issue and no solution above worked for me and it sort of felt like guess work thereafter. However, wrapping my code which creates the object in a setTimeout function did the trick for me.
setTimeout(function() {
var myObj = xyz; //some code for creation of complex object like above
console.log(myObj); // this works
console.log(myObj.propertyName); // this works too
});

I've just had the same issue with a document loaded from MongoDB using Mongoose.
Turned out that i'm using the property find() to return just one object, so i changed find() to findOne() and everything worked for me.
Solution (if you're using Mongoose): Make sure to return one object only, so you can parse its object.id or it will be treated as an array so you need to acces it like that object[0].id.

In My case, it just happens to be that even though i receive the data in the format of a model like myMethod(data:MyModelClass) object till the received object was of type string.
Which is y in console.log(data) i get the content.
Solution is just to parse the JSON(in my case)
const model:MyMOdelClass=JSON.parse(data);
Thought may be usefull.

I've had similar issue, hope the following solution helps someone.
You can use setTimeout function as some guys here suggesting, but you never know how exactly long does your browser need to get your object defined.
Out of that I'd suggest using setInterval function instead. It will wait until your object config.col_id_3 gets defined and then fire your next code part that requires your specific object properties.
window.addEventListener('load', function(){
var fileInterval = setInterval(function() {
if (typeof config.col_id_3 !== 'undefined') {
// do your stuff here
clearInterval(fileInterval); // clear interval
}
}, 100); // check every 100ms
});

if you're using TYPESCRIPT and/or ANGULAR, it could be this!
.then((res: any) => res.json())
setting the response type to any fixed this issue for me, I couldn't access properties on the response until i set res: any
see this question Property '_body' does not exist on type 'Response'

I had a similar issue or maybe just related.
For my case I was accessing properties of an object but one was undefined. I found the problem was a white-space in the server side code while creating the key,val of the object.
My approach was as follows...
After removing the white-space from the server-side code creating the object, I could now access the property as below...
This might not be the issue with the case of the subject question but was for my case and may be so for some one else. Hope it helps.

I just encountered this issue as well, and long story short my API was returning a string type and not JSON. So it looked exactly the same when you printed it to the log however whenever I tried to access the properties it gave me an undefined error.
API Code:
var response = JsonConvert.DeserializeObject<StatusResult>(string Of object);
return Json(response);
previously I was just returning:
return Json(string Of object);

First thing check the type like below:
console.log(typeof config);
If the command above prints object then it is very easy you just use the bracket notation. Bracket notation can be quite useful if you want to search for a property’s values dynamically.
Execute the command below:
console.log(config[col_id_3]);
If it a string you need to parse in object first. To do that you need to execute the command below:
var object = JSON.parse(config);
And after that use bracket notation to access the property like below:
console.log(object[col_id_3]);

I had an issue like this, and found the solution was to do with Underscore.js. My initial logging made no sense:
console.log(JSON.stringify(obj, null, 2));
> {
> "code": "foo"
> }
console.log(obj.code);
> undefined
I found the solution by also looking at the keys of the object:
console.log(JSON.stringify(Object.keys(obj)));
> ["_wrapped","_chain"]
This lead me to realise that obj was actually an Underscore.js wrapper around an object, and the initial debugging was lying to me.

I had similar problem (when developing for SugarCRM), where I start with:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch();
// Here were my attributes filled in with proper values including name
console.log(leadBean);
// Printed "undefined"
console.log(leadBean.attributes.name);
Problem was in fetch(), its async call so I had to rewrite my code into:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch({
success: function (lead) {
// Printed my value correctly
console.log(lead.attributes.name);
}
});

Just in case this is helpful for someone, I had a similar problem, and it's because someone created an override for .toJSON in the object I was working with. So the object was something like:
{
foo: {
bar: "Hello"
baz: "World"
}
}
But .toJSON() was:
toJSON() {
return this.foo
}
So when I called JSON.stringify(myObject) it returned "{"bar": "Hello", "baz": "World"}". However, Object.keys(myObject) revealed the "foo".

I faced the same problem today. In my case the keys were nested, i.e key1.key2.
I split the keys using split() and then used the square bracket notation, which did work for me.
var data = {
key1: {
key2: "some value"
}
}
I split the keys and used it like this, data[key1][key2] which did the job for me.

I had the same issue today. Problem was caused by uglify-js. After I executed same non-uglified code problem was solved. Removing of
--mangle-props
from uglify-js was enough to have working uglified code.
Perhaps, the best practice is to use some prefix for properties that has to be mangled with regex rule for uglify-js.
Here is the source:
var data = JSON.parse( content);
...
this.pageIndex = parseInt(data.index);
this.pageTotal = parseInt(data.total);
this.pageLimit = parseInt(data.limit);
and here is how it was uglified:
var n = JSON.parse( t);
...
this._ = parseInt(n.index), this.g = parseInt(n.total), this.D = parseInt(n.C)

None of the JSON stringify/parse worked for me.
formValues.myKey: undefined
formValues.myKey with timeout: content
I wanted the value of formValues.myKey and what did the trick was a setTimeout 0 like in the example below. Hope it helps.
console.log('formValues.myKey: ',formValues.myKey);
setTimeout( () => {
console.log('formValues.myKey with timeout: ', formValues.myKey);
}, 0 );

I had a similar issue today in React. Eventually realised that the problem was being caused by the state not being set yet. I was calling user.user.name and although it was showing up in the console, I couldn't seem to access it in my component till I included a check to check if user.user was set and then calling user.user.name.

Check whether you had applied any filters in the console. It happens to me in chrome console.

I also had this frustrating problem, I tried the setTimeout() and the JSON.stringify and JSON.parse solutions even if I knew it wouldn't work as I think they're mostly JSON or Promise related problems, sure enough it didn't work. In my case though, I didn't notice immediately that it was a silly mistake. I was actually accessing a property name with a different casing. It's something like this:
const wrongPropName = "SomeProperty"; // upper case "S"
const correctPropName = "someProperty"; // lower case "s"
const object = { someProperty: "hello world!" };
console.log('Accessing "SomeProperty":', object[wrongPropName]);
console.log('Accessing "someProperty":', object[correctPropName])
It took me a while to notice as the property names in my case can have either all lower case or some having mixed case. It turned out that a function in my web application has something that makes a mess of my property names (it has a .toLowerCase() next to the generated key names 🤣).
So, lesson learned, check property name casing more properly.

Related

parsing nested javascript objects [duplicate]

Below, you can see the output from these two logs. The first clearly shows the full object with the property I'm trying to access, but on the very next line of code, I can't access it with config.col_id_3 (see the "undefined" in the screenshot?). Can anyone explain this? I can get access to every other property except field_id_4 as well.
console.log(config);
console.log(config.col_id_3);
This is what these lines print in Console
The output of console.log(anObject) is misleading; the state of the object displayed is only resolved when you expand the Object tree displayed in the console, by clicking on >. It is not the state of the object when you console.log'd the object.
Instead, try console.log(Object.keys(config)), or even console.log(JSON.stringify(config)) and you will see the keys, or the state of the object at the time you called console.log.
You will (usually) find the keys are being added after your console.log call.
I've just had this issue with a document loaded from MongoDB using Mongoose.
When running console.log() on the whole object, all the document fields (as stored in the db) would show up. However some individual property accessors would return undefined, when others (including _id) worked fine.
Turned out that property accessors only works for those fields specified in my mongoose.Schema(...) definition, whereas console.log() and JSON.stringify() returns all fields stored in the db.
Solution (if you're using Mongoose): make sure all your db fields are defined in mongoose.Schema(...).
Check if inside the object there's an array of objects. I had a similar issue with a JSON:
"terms": {
"category": [
{
"ID": 4,
"name": "Cirugia",
"slug": "cirugia",
"description": "",
"taxonomy": "category",
"parent": null,
"count": 68,
"link": "http://distritocuatro.mx/enarm/category/cirugia/"
}
]
}
I tried to access the 'name' key from 'category' and I got the undefined error, because I was using:
var_name = obj_array.terms.category.name
Then I realised it has got square brackets, that means that it has an array of objects inside the category key, because it can have more than one category object. So, in order to get the 'name' key I used this:
var_name = obj_array.terms.category[0].name
And That does the trick.
Maybe it's too late for this answer, but I hope someone with the same problem will find this as I did before finding the Solution :)
I had the same issue. Solution for me was using the stringified output as input to parsing the JSON. this worked for me. hope its useful to you
var x =JSON.parse(JSON.stringify(obj));
console.log(x.property_actually_now_defined);
The property you're trying to access might not exist yet. Console.log works because it executes after a small delay, but that isn't the case for the rest of your code. Try this:
var a = config.col_id_3; //undefined
setTimeout(function()
{
var a = config.col_id_3; //voila!
}, 100);
In my case I was passing an object to a promise, within the promise I was adding more key/values to the object and when it was done the promise returned the object.
However, a slight over look on my part, the promise was returning the object before it was fully finished...thus the rest of my code was trying to process the updated object and the data wasn't yet there. But like above, in the console, I saw the object fully updated but wasn't able to access the keys - they were coming back undefined. Until I saw this:
console.log(obj) ;
console.log(obj.newKey1) ;
// returned in console
> Object { origKey1: "blah", origKey2: "blah blah"} [i]
origKey1: "blah"
origKey2: "blah blah"
newKey1: "this info"
newKey2: "that info"
newKey3: " more info"
> *undefined*
The [i] is a little icon, when I hovered over it it said Object value at left was snapshotted when logged, value below was evaluated just now. Thats when it occurred to me that my object was being evaluated before the promise had fully updated it.
I just encountered this issue with objects generated by csv-parser from a CSV file that was generated by MS Excel. I was able to access all properties except the first property - but it would show up ok if I wrote the whole object using console.log.
Turned out that the UTF-8 CSV format inserts 3 bytes (ef bb bf) at the start corresponding to an invisible character - which were being included as part of the first property header by csv-parser. Solution was to re-generate the CSV using the non-UTF option and this eliminated the invisible character.
I struggled with this issue today, and thought I'll leave a reply with my solution.
I was fetching a data object via ajax, something like this:
{"constants": {"value1":"x","value2":"y"},"i18n" {"data1":"x", "data2":"y"}}
Let's say this object is in a variable called data. Whenever I referenced data.i18n I got undefined.
console.log(data) showed the object as expected
console.log(Object.keys(data)) said ["constants","i18n"] as expected
Renaming i18n to inter didn't change anything
I even tried to switch the data to make "i18n" the first object
Moved code around to make absolutely sure the object was completely set and there was no problem with the ajax promise.
Nothing helped... Then on the server side I wrote the data to the php log, and it revealed this:
{"constants": {"value1":"x","value2":"y"},"\u045618n" {"data1":"x", "data2":"y"}}
The "i" in the index key was actually a u0456 (cyrillic i). This was not visible in my php editor or the browser console log. Only the php log revealed this... That was a tricky one...
My data was just json data string . (This variable was stored as json string in the session).
console.log(json_string_object)
-> returns just the representation of this string and there is no way to make difference whether is string or object.
So to make it work I just needed to convert it back to real object:
object = JSON.parse(json_string_object);
In 2018 Mozilla warns us in the Mozilla Docs here!
I quote "Logging Objects":
Don't use console.log(obj);,
use console.log(JSON.parse(JSON.stringify(obj)));.
This way you are sure you are seeing the value of obj at the moment
you log it.
If this is an issue occurring when working with Mongoose, the following may happen:
console.log(object)
returns everything, including the desired key.
console.log(object.key)
returns undefined.
If that is happening, it means that the key is missing from the Mongoose Schema. Adding it in will resolve the issue.
For me it turned out to be a Mongoose-related problem.
I was looping over objects that I got from a Mongo query. I just had to remove:
items = await Model.find()
And replace it by:
items = await Model.find().lean()
This might help somebody as I had a similar issue in which the JSON.parse() was returning an object that I could print on the console.log() but I couldn't acccess the specific fields and none of the above solution worked for me. Like using the combination of JSON.parse() with JSON.stringify().
var jsonObj = JSON.parse(JSON.stringify(responseText))
// where responseText is a JSON String returned by the server.
console.log(jsonObj) ///Was printing the object correctly
console.log(jsonObj.Body) /// Was printing Undefined
I ended up solving the problem by using a different parser provided by ExtJs Ext.decode();
var jsonObj = Ext.decode(responseText)
console.log(jsonObj.Body) //Worked...
I had the same issue and no solution above worked for me and it sort of felt like guess work thereafter. However, wrapping my code which creates the object in a setTimeout function did the trick for me.
setTimeout(function() {
var myObj = xyz; //some code for creation of complex object like above
console.log(myObj); // this works
console.log(myObj.propertyName); // this works too
});
I've just had the same issue with a document loaded from MongoDB using Mongoose.
Turned out that i'm using the property find() to return just one object, so i changed find() to findOne() and everything worked for me.
Solution (if you're using Mongoose): Make sure to return one object only, so you can parse its object.id or it will be treated as an array so you need to acces it like that object[0].id.
In My case, it just happens to be that even though i receive the data in the format of a model like myMethod(data:MyModelClass) object till the received object was of type string.
Which is y in console.log(data) i get the content.
Solution is just to parse the JSON(in my case)
const model:MyMOdelClass=JSON.parse(data);
Thought may be usefull.
I've had similar issue, hope the following solution helps someone.
You can use setTimeout function as some guys here suggesting, but you never know how exactly long does your browser need to get your object defined.
Out of that I'd suggest using setInterval function instead. It will wait until your object config.col_id_3 gets defined and then fire your next code part that requires your specific object properties.
window.addEventListener('load', function(){
var fileInterval = setInterval(function() {
if (typeof config.col_id_3 !== 'undefined') {
// do your stuff here
clearInterval(fileInterval); // clear interval
}
}, 100); // check every 100ms
});
if you're using TYPESCRIPT and/or ANGULAR, it could be this!
.then((res: any) => res.json())
setting the response type to any fixed this issue for me, I couldn't access properties on the response until i set res: any
see this question Property '_body' does not exist on type 'Response'
I had a similar issue or maybe just related.
For my case I was accessing properties of an object but one was undefined. I found the problem was a white-space in the server side code while creating the key,val of the object.
My approach was as follows...
After removing the white-space from the server-side code creating the object, I could now access the property as below...
This might not be the issue with the case of the subject question but was for my case and may be so for some one else. Hope it helps.
I just encountered this issue as well, and long story short my API was returning a string type and not JSON. So it looked exactly the same when you printed it to the log however whenever I tried to access the properties it gave me an undefined error.
API Code:
var response = JsonConvert.DeserializeObject<StatusResult>(string Of object);
return Json(response);
previously I was just returning:
return Json(string Of object);
First thing check the type like below:
console.log(typeof config);
If the command above prints object then it is very easy you just use the bracket notation. Bracket notation can be quite useful if you want to search for a property’s values dynamically.
Execute the command below:
console.log(config[col_id_3]);
If it a string you need to parse in object first. To do that you need to execute the command below:
var object = JSON.parse(config);
And after that use bracket notation to access the property like below:
console.log(object[col_id_3]);
I had an issue like this, and found the solution was to do with Underscore.js. My initial logging made no sense:
console.log(JSON.stringify(obj, null, 2));
> {
> "code": "foo"
> }
console.log(obj.code);
> undefined
I found the solution by also looking at the keys of the object:
console.log(JSON.stringify(Object.keys(obj)));
> ["_wrapped","_chain"]
This lead me to realise that obj was actually an Underscore.js wrapper around an object, and the initial debugging was lying to me.
I had similar problem (when developing for SugarCRM), where I start with:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch();
// Here were my attributes filled in with proper values including name
console.log(leadBean);
// Printed "undefined"
console.log(leadBean.attributes.name);
Problem was in fetch(), its async call so I had to rewrite my code into:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch({
success: function (lead) {
// Printed my value correctly
console.log(lead.attributes.name);
}
});
Just in case this is helpful for someone, I had a similar problem, and it's because someone created an override for .toJSON in the object I was working with. So the object was something like:
{
foo: {
bar: "Hello"
baz: "World"
}
}
But .toJSON() was:
toJSON() {
return this.foo
}
So when I called JSON.stringify(myObject) it returned "{"bar": "Hello", "baz": "World"}". However, Object.keys(myObject) revealed the "foo".
I faced the same problem today. In my case the keys were nested, i.e key1.key2.
I split the keys using split() and then used the square bracket notation, which did work for me.
var data = {
key1: {
key2: "some value"
}
}
I split the keys and used it like this, data[key1][key2] which did the job for me.
I had the same issue today. Problem was caused by uglify-js. After I executed same non-uglified code problem was solved. Removing of
--mangle-props
from uglify-js was enough to have working uglified code.
Perhaps, the best practice is to use some prefix for properties that has to be mangled with regex rule for uglify-js.
Here is the source:
var data = JSON.parse( content);
...
this.pageIndex = parseInt(data.index);
this.pageTotal = parseInt(data.total);
this.pageLimit = parseInt(data.limit);
and here is how it was uglified:
var n = JSON.parse( t);
...
this._ = parseInt(n.index), this.g = parseInt(n.total), this.D = parseInt(n.C)
None of the JSON stringify/parse worked for me.
formValues.myKey: undefined
formValues.myKey with timeout: content
I wanted the value of formValues.myKey and what did the trick was a setTimeout 0 like in the example below. Hope it helps.
console.log('formValues.myKey: ',formValues.myKey);
setTimeout( () => {
console.log('formValues.myKey with timeout: ', formValues.myKey);
}, 0 );
I had a similar issue today in React. Eventually realised that the problem was being caused by the state not being set yet. I was calling user.user.name and although it was showing up in the console, I couldn't seem to access it in my component till I included a check to check if user.user was set and then calling user.user.name.
Check whether you had applied any filters in the console. It happens to me in chrome console.
I also had this frustrating problem, I tried the setTimeout() and the JSON.stringify and JSON.parse solutions even if I knew it wouldn't work as I think they're mostly JSON or Promise related problems, sure enough it didn't work. In my case though, I didn't notice immediately that it was a silly mistake. I was actually accessing a property name with a different casing. It's something like this:
const wrongPropName = "SomeProperty"; // upper case "S"
const correctPropName = "someProperty"; // lower case "s"
const object = { someProperty: "hello world!" };
console.log('Accessing "SomeProperty":', object[wrongPropName]);
console.log('Accessing "someProperty":', object[correctPropName])
It took me a while to notice as the property names in my case can have either all lower case or some having mixed case. It turned out that a function in my web application has something that makes a mess of my property names (it has a .toLowerCase() next to the generated key names 🤣).
So, lesson learned, check property name casing more properly.

Converting an Array of Objects to a COM Variant Array from JavaScript

I'm currently struggeling a little with a problem concerning an ActiveX-Interface and specifically a Variant-Array. I found some answers how to achieve the conversion but unfortunately nothing worked for me so far. Maybe you can help me. Here's my problem:
I have some Objects i retrieved via the ActiveXInterface. Now one ActiveX-Method requires to have two of these objects in an array.
In VB this is what you basically do
Dim aVar1(1)
Set aVar1(0) = oReferenceLine1
Set aVar1(1) = oReferenceLine2
After that you pass this array to a function like this
Set oNewJoint = oNewMechanism.AddJoint("CATKinCylindricalJoint",aVar1)
Work with everythin i retrieve via the interface works fine, but i am unable to create an array to pass that function. One approach I found to solve this issue was this
var vbArray = new ActiveXObject('Scripting.Dictionary');
$.each(JSArray, function(index){
vbArray.add(index, JSArray[index]);
});
return vbArray.Items();
However if I do this. I just get back an undefined. vbArray gets created and I can access e.g. vbArray.Item(1) but vbArray.Items() just keeps returning undefined and calling the function
var joint = mechanism.ActiveXObject.AddJoint('CATKinCynlindricalJoint', vbArray);
just keeps returning a TypeConflict
It would be great if someone has an idea how I can put those two objects in an array and pass them as a variant array to my Application.
As often I was looking in the wrong direction for the error. Even though I couldn't (and still) can't read the contents of the vbArray it's not empty. After i corrected the typo in 'CATKinCynlindricalJoint'
I noticed that when I used the vbArray.Items() as an argument I got the error that the AddJoint-Method failed. If I just tried the Method with undefined I got a TypeConflict returned. So obviously vbArray.Items() was not really undefined.
After that i noticed that I was using a wrong argument to build my References and conversion to a vbArray did actually work. The error I made goes pretty much into detail with Catia, so I won't dive into it.

How to console.log large object? [duplicate]

This question already has answers here:
How can I get the full object in Node.js's console.log(), rather than '[Object]'?
(19 answers)
Closed 8 years ago.
I'm trying to see what the object contains
With console.log(obj) the console cuts off from the lines and I can't see the entire structure.
Then I tried writing it to a file
fs.writeFile('test', JSON.stringify(obj));
But I get some error about circular references.
Is there any other way to view the object lol? The object is a "connection" from the nodejs websocket module. The docs are very poor and I can't seem to find the property that holds the IP address :(
fs.writeFile('test', JSON.stringify(obj));
But I get some error about circular references.
That's what happens with JSON. JSON also ignores functions, regexes, dates, etc.
You can use util.inspect, which is what Node's console.log() uses internally to get the entire object, which can then be written to a file:
var util = require('util');
fs.writeFileSync('test.txt', util.inspect(obj));
And if you want infinite depth, and hidden properties:
util.inspect(obj, { showHidden: true, depth: null })
Use the dir method.
console.dir(obj)
I've never used console.dir before, and that may very well be the correct way. However, what I've always done is just assign what I want to look at to a global variable, and then play with it directly inside the console.
Something like this:
var x;
function xyz(){
// Code
x = obj;
}
Then, directly in the console, if you type x, after xyz has run, you have your object there, and can play with the copy of it, including the ability to see all the properties, and modify it.
You can use the dir method i believe
console.dir(obj)
You're welcome ;)

Can't access object property, even though it shows up in a console log

Below, you can see the output from these two logs. The first clearly shows the full object with the property I'm trying to access, but on the very next line of code, I can't access it with config.col_id_3 (see the "undefined" in the screenshot?). Can anyone explain this? I can get access to every other property except field_id_4 as well.
console.log(config);
console.log(config.col_id_3);
This is what these lines print in Console
The output of console.log(anObject) is misleading; the state of the object displayed is only resolved when you expand the Object tree displayed in the console, by clicking on >. It is not the state of the object when you console.log'd the object.
Instead, try console.log(Object.keys(config)), or even console.log(JSON.stringify(config)) and you will see the keys, or the state of the object at the time you called console.log.
You will (usually) find the keys are being added after your console.log call.
I've just had this issue with a document loaded from MongoDB using Mongoose.
When running console.log() on the whole object, all the document fields (as stored in the db) would show up. However some individual property accessors would return undefined, when others (including _id) worked fine.
Turned out that property accessors only works for those fields specified in my mongoose.Schema(...) definition, whereas console.log() and JSON.stringify() returns all fields stored in the db.
Solution (if you're using Mongoose): make sure all your db fields are defined in mongoose.Schema(...).
Check if inside the object there's an array of objects. I had a similar issue with a JSON:
"terms": {
"category": [
{
"ID": 4,
"name": "Cirugia",
"slug": "cirugia",
"description": "",
"taxonomy": "category",
"parent": null,
"count": 68,
"link": "http://distritocuatro.mx/enarm/category/cirugia/"
}
]
}
I tried to access the 'name' key from 'category' and I got the undefined error, because I was using:
var_name = obj_array.terms.category.name
Then I realised it has got square brackets, that means that it has an array of objects inside the category key, because it can have more than one category object. So, in order to get the 'name' key I used this:
var_name = obj_array.terms.category[0].name
And That does the trick.
Maybe it's too late for this answer, but I hope someone with the same problem will find this as I did before finding the Solution :)
I had the same issue. Solution for me was using the stringified output as input to parsing the JSON. this worked for me. hope its useful to you
var x =JSON.parse(JSON.stringify(obj));
console.log(x.property_actually_now_defined);
The property you're trying to access might not exist yet. Console.log works because it executes after a small delay, but that isn't the case for the rest of your code. Try this:
var a = config.col_id_3; //undefined
setTimeout(function()
{
var a = config.col_id_3; //voila!
}, 100);
In my case I was passing an object to a promise, within the promise I was adding more key/values to the object and when it was done the promise returned the object.
However, a slight over look on my part, the promise was returning the object before it was fully finished...thus the rest of my code was trying to process the updated object and the data wasn't yet there. But like above, in the console, I saw the object fully updated but wasn't able to access the keys - they were coming back undefined. Until I saw this:
console.log(obj) ;
console.log(obj.newKey1) ;
// returned in console
> Object { origKey1: "blah", origKey2: "blah blah"} [i]
origKey1: "blah"
origKey2: "blah blah"
newKey1: "this info"
newKey2: "that info"
newKey3: " more info"
> *undefined*
The [i] is a little icon, when I hovered over it it said Object value at left was snapshotted when logged, value below was evaluated just now. Thats when it occurred to me that my object was being evaluated before the promise had fully updated it.
I just encountered this issue with objects generated by csv-parser from a CSV file that was generated by MS Excel. I was able to access all properties except the first property - but it would show up ok if I wrote the whole object using console.log.
Turned out that the UTF-8 CSV format inserts 3 bytes (ef bb bf) at the start corresponding to an invisible character - which were being included as part of the first property header by csv-parser. Solution was to re-generate the CSV using the non-UTF option and this eliminated the invisible character.
I struggled with this issue today, and thought I'll leave a reply with my solution.
I was fetching a data object via ajax, something like this:
{"constants": {"value1":"x","value2":"y"},"i18n" {"data1":"x", "data2":"y"}}
Let's say this object is in a variable called data. Whenever I referenced data.i18n I got undefined.
console.log(data) showed the object as expected
console.log(Object.keys(data)) said ["constants","i18n"] as expected
Renaming i18n to inter didn't change anything
I even tried to switch the data to make "i18n" the first object
Moved code around to make absolutely sure the object was completely set and there was no problem with the ajax promise.
Nothing helped... Then on the server side I wrote the data to the php log, and it revealed this:
{"constants": {"value1":"x","value2":"y"},"\u045618n" {"data1":"x", "data2":"y"}}
The "i" in the index key was actually a u0456 (cyrillic i). This was not visible in my php editor or the browser console log. Only the php log revealed this... That was a tricky one...
My data was just json data string . (This variable was stored as json string in the session).
console.log(json_string_object)
-> returns just the representation of this string and there is no way to make difference whether is string or object.
So to make it work I just needed to convert it back to real object:
object = JSON.parse(json_string_object);
In 2018 Mozilla warns us in the Mozilla Docs here!
I quote "Logging Objects":
Don't use console.log(obj);,
use console.log(JSON.parse(JSON.stringify(obj)));.
This way you are sure you are seeing the value of obj at the moment
you log it.
If this is an issue occurring when working with Mongoose, the following may happen:
console.log(object)
returns everything, including the desired key.
console.log(object.key)
returns undefined.
If that is happening, it means that the key is missing from the Mongoose Schema. Adding it in will resolve the issue.
For me it turned out to be a Mongoose-related problem.
I was looping over objects that I got from a Mongo query. I just had to remove:
items = await Model.find()
And replace it by:
items = await Model.find().lean()
This might help somebody as I had a similar issue in which the JSON.parse() was returning an object that I could print on the console.log() but I couldn't acccess the specific fields and none of the above solution worked for me. Like using the combination of JSON.parse() with JSON.stringify().
var jsonObj = JSON.parse(JSON.stringify(responseText))
// where responseText is a JSON String returned by the server.
console.log(jsonObj) ///Was printing the object correctly
console.log(jsonObj.Body) /// Was printing Undefined
I ended up solving the problem by using a different parser provided by ExtJs Ext.decode();
var jsonObj = Ext.decode(responseText)
console.log(jsonObj.Body) //Worked...
I had the same issue and no solution above worked for me and it sort of felt like guess work thereafter. However, wrapping my code which creates the object in a setTimeout function did the trick for me.
setTimeout(function() {
var myObj = xyz; //some code for creation of complex object like above
console.log(myObj); // this works
console.log(myObj.propertyName); // this works too
});
I've just had the same issue with a document loaded from MongoDB using Mongoose.
Turned out that i'm using the property find() to return just one object, so i changed find() to findOne() and everything worked for me.
Solution (if you're using Mongoose): Make sure to return one object only, so you can parse its object.id or it will be treated as an array so you need to acces it like that object[0].id.
In My case, it just happens to be that even though i receive the data in the format of a model like myMethod(data:MyModelClass) object till the received object was of type string.
Which is y in console.log(data) i get the content.
Solution is just to parse the JSON(in my case)
const model:MyMOdelClass=JSON.parse(data);
Thought may be usefull.
I've had similar issue, hope the following solution helps someone.
You can use setTimeout function as some guys here suggesting, but you never know how exactly long does your browser need to get your object defined.
Out of that I'd suggest using setInterval function instead. It will wait until your object config.col_id_3 gets defined and then fire your next code part that requires your specific object properties.
window.addEventListener('load', function(){
var fileInterval = setInterval(function() {
if (typeof config.col_id_3 !== 'undefined') {
// do your stuff here
clearInterval(fileInterval); // clear interval
}
}, 100); // check every 100ms
});
if you're using TYPESCRIPT and/or ANGULAR, it could be this!
.then((res: any) => res.json())
setting the response type to any fixed this issue for me, I couldn't access properties on the response until i set res: any
see this question Property '_body' does not exist on type 'Response'
I had a similar issue or maybe just related.
For my case I was accessing properties of an object but one was undefined. I found the problem was a white-space in the server side code while creating the key,val of the object.
My approach was as follows...
After removing the white-space from the server-side code creating the object, I could now access the property as below...
This might not be the issue with the case of the subject question but was for my case and may be so for some one else. Hope it helps.
I just encountered this issue as well, and long story short my API was returning a string type and not JSON. So it looked exactly the same when you printed it to the log however whenever I tried to access the properties it gave me an undefined error.
API Code:
var response = JsonConvert.DeserializeObject<StatusResult>(string Of object);
return Json(response);
previously I was just returning:
return Json(string Of object);
First thing check the type like below:
console.log(typeof config);
If the command above prints object then it is very easy you just use the bracket notation. Bracket notation can be quite useful if you want to search for a property’s values dynamically.
Execute the command below:
console.log(config[col_id_3]);
If it a string you need to parse in object first. To do that you need to execute the command below:
var object = JSON.parse(config);
And after that use bracket notation to access the property like below:
console.log(object[col_id_3]);
I had an issue like this, and found the solution was to do with Underscore.js. My initial logging made no sense:
console.log(JSON.stringify(obj, null, 2));
> {
> "code": "foo"
> }
console.log(obj.code);
> undefined
I found the solution by also looking at the keys of the object:
console.log(JSON.stringify(Object.keys(obj)));
> ["_wrapped","_chain"]
This lead me to realise that obj was actually an Underscore.js wrapper around an object, and the initial debugging was lying to me.
I had similar problem (when developing for SugarCRM), where I start with:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch();
// Here were my attributes filled in with proper values including name
console.log(leadBean);
// Printed "undefined"
console.log(leadBean.attributes.name);
Problem was in fetch(), its async call so I had to rewrite my code into:
var leadBean = app.data.createBean('Leads', {id: this.model.attributes.parent_id});
// This should load object with attributes
leadBean.fetch({
success: function (lead) {
// Printed my value correctly
console.log(lead.attributes.name);
}
});
Just in case this is helpful for someone, I had a similar problem, and it's because someone created an override for .toJSON in the object I was working with. So the object was something like:
{
foo: {
bar: "Hello"
baz: "World"
}
}
But .toJSON() was:
toJSON() {
return this.foo
}
So when I called JSON.stringify(myObject) it returned "{"bar": "Hello", "baz": "World"}". However, Object.keys(myObject) revealed the "foo".
I faced the same problem today. In my case the keys were nested, i.e key1.key2.
I split the keys using split() and then used the square bracket notation, which did work for me.
var data = {
key1: {
key2: "some value"
}
}
I split the keys and used it like this, data[key1][key2] which did the job for me.
I had the same issue today. Problem was caused by uglify-js. After I executed same non-uglified code problem was solved. Removing of
--mangle-props
from uglify-js was enough to have working uglified code.
Perhaps, the best practice is to use some prefix for properties that has to be mangled with regex rule for uglify-js.
Here is the source:
var data = JSON.parse( content);
...
this.pageIndex = parseInt(data.index);
this.pageTotal = parseInt(data.total);
this.pageLimit = parseInt(data.limit);
and here is how it was uglified:
var n = JSON.parse( t);
...
this._ = parseInt(n.index), this.g = parseInt(n.total), this.D = parseInt(n.C)
None of the JSON stringify/parse worked for me.
formValues.myKey: undefined
formValues.myKey with timeout: content
I wanted the value of formValues.myKey and what did the trick was a setTimeout 0 like in the example below. Hope it helps.
console.log('formValues.myKey: ',formValues.myKey);
setTimeout( () => {
console.log('formValues.myKey with timeout: ', formValues.myKey);
}, 0 );
I had a similar issue today in React. Eventually realised that the problem was being caused by the state not being set yet. I was calling user.user.name and although it was showing up in the console, I couldn't seem to access it in my component till I included a check to check if user.user was set and then calling user.user.name.
Check whether you had applied any filters in the console. It happens to me in chrome console.
I also had this frustrating problem, I tried the setTimeout() and the JSON.stringify and JSON.parse solutions even if I knew it wouldn't work as I think they're mostly JSON or Promise related problems, sure enough it didn't work. In my case though, I didn't notice immediately that it was a silly mistake. I was actually accessing a property name with a different casing. It's something like this:
const wrongPropName = "SomeProperty"; // upper case "S"
const correctPropName = "someProperty"; // lower case "s"
const object = { someProperty: "hello world!" };
console.log('Accessing "SomeProperty":', object[wrongPropName]);
console.log('Accessing "someProperty":', object[correctPropName])
It took me a while to notice as the property names in my case can have either all lower case or some having mixed case. It turned out that a function in my web application has something that makes a mess of my property names (it has a .toLowerCase() next to the generated key names 🤣).
So, lesson learned, check property name casing more properly.

console.log() showing contradictory values for the same object property

I think i might be going mad.
I use console.log() to see the state of an object and then on the next line do a console.log() on a particular property of the same object and get different values for each.
The code i'm using is:
console.log(this.pictures.Items[pic].val);
for(var i in this.pictures.Items[pic].val) {
console.log("property: %s, value: %s", i, this.pictures.Items[pic].val[i] );
}
and firebug outputs:
Picture { isLoaded=true, isSelected=false, img_src="imgs/image1.jpg", more...}
property: isLoaded, value: false
...more properties
as you can see, 'isLoaded' is true when logging the object itself but false when logging the property.
I have tried logging the object again after just in case, and it is true again.
Does anyone know what is happening here?
Thanks
Rich
I'm not entirely sure if this is what is happening to you or not, but console.log() seems to have some issues in some browsers where doing a console.log() on a value or using an index variable that is changing or being iterated in an array does not always work properly.
My guess is that it has something to do with things getting marshalled between process boundaries and perhaps a delay in the actual evaluation of the logging expression until a time in which the actual object or index being used or referenced has changed. I've seen this issue in Chrome for sure - don't know about Firefox.
You should be able to work around this particular issue by using string math to build your final string. If only the final string is passed to console.log() where everything is fully evaluated, then this issue would not impact the output.

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