json - Add dynamic key, value pairs to JavaScript array or hash table

Question

I'm trying to add a key value pair to an existing javascript associative array. The key needs to be a variable. This is for JSON encoding. I realize there are many plugins and frameworks for this, but I want a simple answer.

ary.push({name: val});

where ary is a new array, name is a variable containing the key, val is the value of this entry.

I'm doing this in a jQuery loop that iterates through form fields.

Answer 1

In ES6...

In ES6, you can use a destructuring assignment;

ary.push({[name]: val});

However, given this is ES6 syntax, the usual caveats apply; this will not work in some browsers (noticably, IE and Edge 13)... although Babel will transpile this for you.

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Without ES6 (legacy browser support)...

You need to define an object and use square bracket notation to set the property;

var obj = {};

obj[name] = val;

ary.push(obj);

If you get the urge to read into it more, see this article on the differences between square bracket and dot notation.