var curr = data[i],
newArray = [],
key = curr.Frequency.Type,
obj = {key: []};
newArray.push(obj);
However, this yields an object with a key of "key"! How can I create a new object with a key of the value of the variable key?
You can do this:
var curr = data[i],
newArray = [],
key = curr.Frequency.Type,
obj = {};
obj[key] = [];
newArray.push(obj);
There's no way to do it in JavaScript within the object literal itself; the syntax just doesn't provide for that.
edit — when this answer was written, the above was true, but ES2015 provides for dynamic keys in object initializers:
var curr = data[i],
key = curr.Frequency.Type,
newArray = [ { [key]: [] } ];
I think you mean this notation:
var type = "some type";
var obj = {}; // can't do it one line
obj[type] = [];
console.log(obj); // { "some type": [] }
simply instantiate a new anonymous object from a function.
obj = new function () {
this[key] = [];
};
I realise this is an old question but for those finding this through Google the way to do this with ES6+ is to use square bracket notation in the object literal:
const key = 'dynamicKey';
const value = 5;
const objectWithDynamicKey = {
staticKey: 'another value',
[key]: value
}
console.log(objectWithDynamicKey)
Which prints:
{
staticKey: 'another value',
dynamicKey: 5
}
So your example should be:
var curr = data[i];
var newArray = [];
var key = curr.Frequency.Type;
var obj = { [key]: [] };
newArray.push(obj);
