[javascript] JavaScript Array Push key value

Ok, I'm going a little wrong here and I've already wasted an hour with this so hopefully one of you guys can help me.

var a = ['left','top'],
    x = [];

for(i=0;i<a.length;i++) {
    x.push({
        a[i] : 0
    });
}

How do I go about pushing a value to each of the keys inside the var a array?

You can see my failed attempted but hopefully that will give you an insight into what I'm trying to achieve.

You may use:

• Array.prototype.map()
• Array.prototype.reduce()
• Arrow functions
• Comma operator

To create array of objects:

var source = ['left', 'top'];
const result = source.map(arrValue => ({[arrValue]: 0}));

Demo:

var source = ['left', 'top'];_x000D_
_x000D_
const result = source.map(value => ({[value]: 0}));_x000D_
_x000D_
console.log(result);

Or if you wants to create a single object from values of arrays:

var source = ['left', 'top'];
const result = source.reduce((obj, arrValue) => (obj[arrValue] = 0, obj), {});

Demo:

var source = ['left', 'top'];_x000D_
_x000D_
const result = source.reduce((obj, arrValue) => (obj[arrValue] = 0, obj), {});_x000D_
_x000D_
console.log(result);