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

function map(square,a) {
  var result = [];
  for(var i=0;i<=a.length-1;i++)
   result[i]=square(a[i]);
  return result;
}

var square = function(x) {
   return x*x;
}

var value=[1,2,3,4];
var final= map(square,value);
console.log(final);

You can also try the above code snippet.