Dynamically add object in javascript array

Question

I have json:

var obj = '{"Form":[],"Provider":[]}';

I push the data with variable value to make dynamic objects:

var pName = 'Tester';
var data = {
 pName :["testing"]
};
console.log(obj['Provider'].push(data));

But that adds pName as variable name but not variable value that is Tester, i tried with +pName+ that also not works.

Returns:

{"Form":[],"Provider":[{"pName":["Testing"]}]}

Any help would be appreciated.

• user663031: You cannot take a property such as Provider of a JSON string; you must first convert the string into a JavaScript object with JSON.parse() (or specify it as a JavaScript object literal to start with).

Answer 1

You must use [] syntax near the property name.It will evaluate the expression in the [] and returns the value.

See the example.Here the data's property is with the name 'Tester'.

var obj = {"Form":[],"Provider":[]};
var pName = 'Tester';
var data = {
 [pName] :["testing"]
};
console.log(data.pName); // undefined
console.log(data.Tester); // OK
obj['Provider'].push(data);
console.log(obj);

• user6302777: I am about to answer this one. Haha. Great job sir. Cheers!
• user663031: if you're going to introduce the [keyname]: value syntax, you should at least give the proper name for this construct. Also, to be precise, this syntax does not "return" the value; it uses the value as the key name. Finally, you omitted any mention of the OP's issue with trying to manipulate a JSON string without converting it into a JavaScript object first.