Square each number in an array in javascript

Question

I\'m trying to square each number in an array and my original code didn\'t work. I looked up another way to do it, but I\'d like to know WHY the original code didn\'t work.<

Answer 1

Here is how it can be done, using a simple method called .forEach

var numbers = [1,2,3,4,5,6,7,8];
numbers.forEach(function(element, index, array){
    array[index] = element* element;
});
console.log(numbers);

Answer 2

The first sample is taking the square root, not squaring the value. To square you want to use

Math.pow(arr[i],2);