How can test over an object like the array.every() method? Trying to detect if all the terms in a query object are blank before sending it on. Obviously I could just write a little routine in a for loop, but I'm expecting there's a more succinct way of accomplishing this.
// array - works
var queryArr = [ "", "" ];
if(!queryArr.every(function(el, i, arr) { return el == "" } )) {
alert("nothing to search");
}
// object - "undefined is not a function"
var queryObj = { term1: "", term2: "" };
if(!queryObj.every(function(el, i, arr) { return el == "" } )) {
alert("nothing to search");
}
Map can be used call a function on each object in an array.
http://api.jquery.com/jquery.map/
You could implement your own every method this way:
Object.prototype.every=function(evalFunction){
var self=this,
property;
if(typeof evalFunction!=='function')
return evalFunction;
for(property in self){
if(self.hasOwnProperty(property) && !evalFunction(self[property], property, self)){
return false;
}
}
return true;
}
Then you could use the new every method on objects the same way you do with arrays But if you only want to test this once on your code I sugest to use for in loop or robisrob's map solution
Related
I have an object structure like as mentioned below in link
https://jsonblob.com/3511b867-dd4b-11e9-85e4-63b804994c26
I want to search say firstname: Dianca in all the nodes under persons using lodash.
I do not want to harcode the node names as that way i have mention a lot of nodes to look for. I need to search it dynamically under person node no matter where it is located under Object structure.
I have tried a way like as below but in vain(like harcoded stuff)
_.filter(users, o =>
_.some(o.Positions, ['persons.firstname', 'Dianca'])
)
and secondly, i want to get all names under persons node and save it to new array..
Any assistance would be appreciated.
What a Question !! It took me an year to build a logic for you :)
function findUser(data, firstName) {
var object;
data.some(function f(a) {
if (a.firstname == firstName) {
object = a;
return true;
}
_.each(Object.keys(a), function (value, key) {
// loops through json objects in waypath
if (!_.isEmpty(object)) {
return false; // stop once we get the user
}
if (isNaN(value)) {
// only data with string keys need to iterate more
// when there is an array with elements
if (Array.isArray(a[value]) && a[value].length != 0) {
a[value].some(f); // recursion (Didn't use return because we are in loop)
} else if (!_.isEmpty(a[value])) {
// when there is an object within object
_.each(Object.keys(a[value]), function (val, key2) {
if (Array.isArray(a[value][val]) && a[value][val].length != 0) {
a[value][val].some(f); // recursion
}
});
}
}
});
});
return object;
}
console.log(findUser(data, "Phyllis"));
Should be exactly what you need. Enjoy !!
This question already has answers here:
Test for existence of nested JavaScript object key
(64 answers)
Closed 6 years ago.
In many places in my code, I have checks similar to the one below. It's very verbose, and ugly. Is there is better way? FYI, I'm using Lodash in all my projects, so I have access to that powerful library.
if (myAssessments[orderId].report &&
myAssessments[orderId].report[categoryProductCode] &&
myAssessments[orderId].report[categoryProductCode].categories &&
myAssessments[orderId].report[categoryProductCode].categories[comment.categoryId]) {
// Do something related to
// myAssessments[orderId].report[categoryProductCode].categories[comment.categoryId]
}
Since you use lodash, you might use the has method:
_.has(obj,[orderId, 'report', categoryProductCode, 'categories', comment.categoryId])
https://lodash.com/docs/4.16.6#has
Or the get method to get the value of the object path: https://lodash.com/docs/4.16.6#get
Not elegant way but you can wrap in try catch
var result;
try{
result = myAssessments[orderId].report[categoryProductCode].categories[comment.categoryId]
}catch{}
if (result){
// do it
}
Use the built-in isset function:
if (isset(myAssessments[orderId].report) &&
isset(myAssessments[orderId].report[categoryProductCode]) &&
isset(myAssessments[orderId].report[categoryProductCode].categories) &&
isset(myAssessments[orderId].report[categoryProductCode].categories[comment.categoryId)]) {
You could use an array with all properties to check and iterate until all properties have been checked.
function checkProperties(object, keys) {
return keys.every(function (key) {
if (key in object) {
object = object[key];
return true;
}
});
}
// usage
if (checkProperties(myAssessments, [orderId, 'report', categoryProductCode, 'categories', comment.categoryId])) {
// Do something related to
// myAssessments[orderId].report[categoryProductCode].categories[comment.categoryId]
}
I have this genric function
function chckForKeyPresence(data, arr, checkLength){
var currData = data;
for(var i=0; i<arr.length; i++){
if(!currData.hasOwnProperty(arr[i]))
return false;
currData = currData[arr[i]];
}
if(checkLength)
if(currData.length==0)
return false;
return true;
}
Here 1st argument is the main data, 2nd argument is the array of properties you need to check and the third argument will check the length of the last element that it is 0 or not, it will check only if the third argument is true.
You can use it like:
if(!chckForKeyPresence(data, ["results", "tweets"], true)){
// error
return;
}
I have an object in javaScript:
var stuffObject = {
stuffArray1 : [object1, object2, object3],
stuffArray2 : [object4, object5, object6]
}
object1 to 6 look like this:
object1 = {
dataStuff : {
stuffId: "foobar"
}
}
My question: given the key "foobar", how do I retrieve object1 from the stuffObject using jQuery? The key "stuffId" always has a unique value.
You won't get around iterating over the set to find the object you are looking for. jQuery can't really help with that. Its purpose is DOM manipulation. If you want functionality to deal with objects, sets, lists, etc., check out lodash.
I wrote a function to deal with the problem. I hope it's understandable.
var stuffObject = {
stuffArray1 : [{dataStuff: {stuffId: 'foobar'}}, {dataStuff: {stuffId: 'foo'}}, {}],
stuffArray2 : [{}, {dataStuff: {stuffId: 'bar'}}, {}]
}
function getObjByStuffId(stuffObject, stuffId) {
var key, arr, i, obj;
// Iterate over all the arrays in the object
for(key in stuffObject) {
if(stuffObject.hasOwnProperty(key)) {
arr = stuffObject[key];
// Iterate over all the values in the array
for(i = 0; i < arr.length; i++) {
obj = arr[i];
// And if it has the value we are looking for
if(typeof obj.dataStuff === 'object'
&& obj.dataStuff.stuffId === stuffId) {
// Stop searching and return the object.
return obj;
}
}
}
}
}
console.log('foobar?', getObjByStuffId(stuffObject, 'foobar') );
console.log('foo?', getObjByStuffId(stuffObject, 'foo') );
console.log('bar?', getObjByStuffId(stuffObject, 'bar') );
Thanks for the help guys, using the input of other people I have solved it myself:
getStuffById: function(id){
for (stuffArray in stuffObject) {
for (stuff in stuffObject[stuffArray]) {
if (stuffObject[stuffArray][stuff].dataStuff.stuffId == id) {
return stuffObject[stuffArray][stuff];
}
}
}
return null;
}
This also works better than the (now deleted) answer that uses .grep(), as this function terminates as soon as it finds the correct object.
I have a dictionary:
[ object , object, object, object, object ]
object contains: id and name.
I have an Id ('123456') and I want to get the object with this id.
Is there another solution how can I do it without for loop on the objects?
any help appreciated!
Hate loops, then go for recursion, i just assumed that you are having that array in a variable called as xArr
var xObj = check(0,"123456");
function check(cnt,id) {
if(xArr[cnt].id === id)
{
return xArr[cnt];
}
else if(cnt === xArr.length - 1) {
return null;
}
else {
cnt += 1;
return check(cnt, id);
}
}
That's an array, you could use jQuery.grep to get the elements with id "123456".
var result = $.grep(arr, function(obj) {
return obj.id === '123456';
});
Array also provide an .filter method (need a polyfill for browsers not support it):
var result = arr.filter(function(obj) {
return obj.id === '123456';
});
If you want to use a vanilla JS method, you can use filter. This pretty much does the same as $.grep.
var result = arr.filter(function (obj) {
return obj.id === '123456';
});
I am not sure on the use of indexOf in arrays of objects
The code which is not working is:
if (res.locals.company.companies.indexOf(req.query.companyId) >= 0) return next()
The if condition will always return false.
I also tested in console and it is actually wrong:
>> var zio = { __v: 1,
_id: '50bc0238049a1ff10b000001',
companies:
[ { _id: '50bc01938f164ee80b000001', name: 'Test' },
{ _id: '50bc01ac4e860ee90b000001', name: 'zio' } ],
}
>> zio.companies.indexOf("50bc01938f164ee80b000001")
-1
whereas it should be true.
Should I use any mysterious underscore utility ?
UPDATE/Clarification: my aim is just to check if 50bc01938f164ee80b000001 exists in one of the ids, I don't need to know where it actually is. This is very performance critical!
Nodejs solutions or tips would be amazing!
It's not wrong. That Array does not contain a String like that, but only two Object references. Hence, the result is correctly -1.
To get the index from the Object reference containing the searched string value, we could go like
var index;
zio.companies.some(function( obj, idx ) {
if( obj._id === '50bc01938f164ee80b000001' ) {
index = idx;
return true;
}
});
console.log('index is: ', index);
Based on your ninja edit, if you just want to know whether or not an object ref holding a specific id is contained by that array, use it like
var check = zio.companies.filter(function( obj ) {
return obj._id === '50bc01938f164ee80b000001';
});
if( check.length ) {
console.log('yep');
} else {
console.log('nope');
}
Second edit: If you are really and only after performance, you probably don't want to have any function call overhead in any search. I'd use something like
function inObject(arr, search) {
var len = arr.length;
while( len-- ) {
if(arr[len]._id === search)
return true;
}
}
if( inObject( zio.companies, 'AAA' ) ) {
}
That code outclasses any snippet provided here by a few magnitudes. See Here
You'll need to loop over the elements and check for the _id being equal.
indexOf checks for strict equality, and those objects are of course not equal to that string. (It's the same logic as "hello" === {foo: "hello"}. That will always be false.)
I'm sure with node there's some fancy way to do that, but the bare-JS way is:
var i,
arr = [{foo: 'bar'}, {foo: 'baz'}],
idx = -1;
for (i = 0; i < arr.length; ++i) {
if (arr[i].foo === 'bar') {
idx = i;
break;
}
}
You could also easily turn that into a function:
function indexOf(arr, pred) {
for (var i = 0; i < arr.length; ++i) {
if (pred(arr)) {
return i;
}
}
return -1;
}
That would give you a lot more verbose usage though (and a bit worse performance), but it might also be a bit more flexible if you find yourself needing to do it often.
console.log(indexOf(arr, function(elem) { return elem.foo === 'bar'; });
.indexOf is returning the correct output; your array doesn't have an element with that string. In fact, it's an array holding two object literals. You don't need .indexOf for objects, instead we must make our own function:
var inObject = function( object, val ) {
for (var i in object) { if ( object.hasOwnProperty(i) ) {
if ( obj[i] === val ) {
return true;
}
}
}
return false;
};
>>> inObject( zio.companies[0], '50bc01938f164ee80b000001' );
: true
Your companies seems to be an array of objects (not ids), which has Id as one of the attributes. indexOf function is used to find the index of the matching element. Since you are passing an ID value to search the index, its not finding it as an element on the array hence returning false.
To fix the problem, you have two options:
Iterate the companies element compare the ID value, if matched return true otherwise false.
Use the object with desired id in as argument in the indexOf function. If value is greater than -1, return true otherwise false.