Using Numbers as a Key Value in Objects

How can I make this work?

// JavaScript Document
var sampleArray = [1,2,3,4,5];
var double = function(num){
    return (num * 2);
};
var doubledNum = new Object();
 
for(var i = 0; i < sampleArray.length; i++){
    doubledNum.sampleArray[i] = double(sampleArray[i]);
}

Code (markup):

 

Okay so I have found that using numbers cannot be done. So using number notation should look like:

console.log(doubledNum.['1']);

Code (markup):

This should print out the number 2 correct?

 

Solved:

// JavaScript Document
var sampleArray = [1,2,3,4,5];
var doubledNum = new Object();
var double = function(num){
    return (num * 2);
};
 
for(var i = 0; i < sampleArray.length; i++){
    doubledNum[sampleArray[i]] = double(sampleArray[i]);
};
 
console.log (doubledNum);

Code (markup):

 

Nice. If your browser supports Array.forEach, you could shorten that:

var numbers = [1, 2, 3, 4, 5];
var doubled = {};

numbers.forEach(function (val, i, arr) {
    doubled[val] = val * 2;
});

Code (markup):