We Keep Coding

Adding key value pair into a JSON object dynamically and accessing the updated object in javascript/Node js

The scenario is there will be three javascript files named js_file1.js , js_file2.js and js_file3.js.
I need to declare a JSON object in js_file1.js like the below one :
let configObject = {
key1:"Value1",
key2:"Value2"
};
now I am exporting it by:
module.exports={
configObject:configObject
};
now I am using it in js_file2.js by js_fileObject1.configObject and adding one more key value pair to it like:
js_fileObject1.configObject.key3 = "value3";
now I need to access this updated object into js_file3.js.
any suggestions to achieve this ? I am losing the last key value pair in js_file3.js and only the original one is coming.

Javascript - key and value in array

I wish to store some data dynamically in an array, using Javascript. My goal is to save a configuration, that the user has specified, and later store it in my database.
I am trying to create a array like this:
var config = [];
config.push({id:100,name:'Yashwant',age:30});
config.push({id:200,name:'Mahesh',age:35});
However, when I print out the config array, like this:
alert(config);
it prints:
[object Object],[object Object]
How can I store and push values to my array, dynamically?
EDIT:: Seems like I am storing the values correctly. How can I access it?

Alert casts the config parameter to string. If you want to see the value for debugging purposes, it is better to use console.log(config).
Or you could use JSON.stringify(config) to convert it to JSON string.
To access the values, you can do this: console.log(config[0].age, config[1].age);

If you want to print values of any javascript object you can use JSON class to either stringify object data or parse stringified data (JSON) back to object.
alert(JSON.stringify(config));

Get value from json "undefined" what I have wrong?

I have this string:
[
{"id":"001",
"name":"Charlie"},
{"id":"002",
"name":"Ellie"},
]
Them, I save this string in a variable and I parse it:
function parseJSON(string){
var mylovelyJSON = JSON.stringify(string);
alert(mylovelyJSON[id]);
}
When I make my alert, I get and "undefined", I also tried with "mylovelyJSON.id", And I get the same.
Could not be a Json? I get this string from an php array.

There are many things wrong here
Your JSON is invalid
You have an extra , just before the end of the array that you need to remove
You need to parse
JSON.stringify converts a JavaScript data structure into a string of JSON.
You need to go the other way and use JSON.parse.
Square-bracket notation takes strings
mylovelyJSON[id] takes the value of id (which is undeclared so, in this case, would throw a reference error) and gets the property with the name that is the same as that value.
You need either mylovelyJSON["id"] or mylovelyJSON.id
You have an array
Your JSON consists of an array of objects, not a single object.
You need to get an object out of the array before you can access properties on it.
mylovelyJSON[0]["id"]
var json_text = '[{"id":"001","name":"Charlie"},{"id":"002","name":"Ellie"}]';
parseJSON(json_text);
function parseJSON(string){
var result_of_parsing_json = JSON.parse(string);
document.body.appendChild(
document.createTextNode(result_of_parsing_json[0]["id"])
);
}

Two things are wrong here
Your array ends with a comma, which isn't valid json
You are converting a string to javascript, and stringify does the opposite of that.
So something like this might work:
var id = 0;
function parseJSON(string){
var mylovelyJSON = JSON.parse(string);
alert(mylovelyJSON[id]);
}
Note I am assuming that id is a global variable...

How do I attach JSON Stringify to a javascript variable

I have a variable :
var testData;
And I have a function that populates an array. Goes through an array and makes another array like so :
var person = {
"Name": obj.Name,
"Age": obj.Age,
}
partsObject.push(person);
I then want to make this array into JSON so I can use it with my D3 objects, so I do this :
testData = JSON.stringify(partsObject);
I can console log this variable, but when trying to go through it via D3's forEach method like so :
testData.forEach(function(d) // data is the JSON
{
I get the error Uncaught TypeError: testData.forEach is not a function
I don't understand how I can log the variable to the console yet it's as if I can't use it as JSON. Any ideas ?

As the name suggests stringify() converts a JavaScript object (the JSO in JSON) into a string of JSON. You can console.log() it because console.log expects to take a string, and anything that's not a string is converted to one to be displayed.
If you want to use it as an array again, you need to parse your string of JSON back to the JavaScript object: JSON.parse(testData).

You really dont need to stringify your Array to pass to d3. Do not to get confused with javascript objects, since forEach requires an array to loop through and you are passing a string to manipulate with forEach function
use:
partsObject.forEach(function(d)
{
...
JSON.stringify(partsObject); creates a string as"{'Name':'ABC','Age':23}"
Uncaught TypeError: testData.forEach is not a function caused because javascript was not able to find an Array

.stringify() turns a Javascript Object into a string. You would want to either run
partsObjects.forEach()
or alternativily you could turn the stringify'ed string back into an object with
(JSON.parse(testData)).forEach()

You are currently trying to loop through a String since you stringify your array.
Just do partsObject.forEach and don't stringify your Array.

how to get the value 'dynamically' from an associative array in javascript?

i am trying to get a value from a key stored on a string variable proyNombre, but whenever i call it via the common method "myAssociativeArray.MyKey", it gets the variable 'proyNombre' as the key, instead of getting its value and passing it as a key.
proyectos.each(function(index){
var proyNombre = this.value;
if(!(proyNombre in myArray)){ // whenever the variable is undefined, define it
myArray[proyNombre] = horas[index].value-0 + minutos[index].value/60;
}
else{
console.log(myArray.proyNombre); //This doesnt work, it tries to give me the value for the key 'proyNombre' instead of looking for the proyNombre variable
console.log(myArray.this.value); //doesnt work either
}
});

Try:
console.log(myArray[proyNombre]);
myArray is actually an object in javascript. You can access object properties with object.propertyName or, object['propertyName']. If your variable proyNombre contained the name of a property (which it does) you can use the second form, like I did above. object.proyNombre is invalid - proyNombre is a variable. You can't do for example:
var myObject = {};
myObject.test = 'test string';
var s = 'test';
console.log(myObject.s); // wrong!!
but you could then do:
console.log(myObject.test);
console.log(myObject['test']);
console.log(myObject[s]);

You need to use the same syntax you used to set the value:
console.log(myArray[proyNombre]);

Simply access the value with myArray[proyNombre].

You're doing it right in the assignment: myArray[proyNombre]. You can use the same method to retrieve the variable.
If you change:
console.log(myArray.proyNombre);
console.log(myArray.this.value);
to
console.log(myArray[proyNombre]);
console.log(myArray[this.value]);
You should get the same value (the value for the key represented by the variable proyNombre) logged twice.
It's true that Javascript doesn't have associative arrays but objects in Javascript can be treated like associative arrays when accessing their members.