Variable scope in Javascript for loop

Question

What\'s the difference between:

function bar()
{
  for (x=0; x< 100; x++) {}
}

And

function bar()
{
  var x;
  for (x=0;         


        

Answer 1

The first example will either add or modify the global variable x, which is generally to be avoided if not the desired outcome.

While your second example works as desired (no side effects) an alternative that looks better in my opinion would be

function bar()
{
  for (var x=0; x< 100; x++) {}
}