forEach Question...

Question

Im currently learning javascript and I just cant seem to understand the forEach method... can someone pleeassseee tell me what this is in the most simplest way. and if u wouldn't mind give an example. Thank You!

Answer 1

This code:
function f(item, index) {}
var num = [3, 2, 1];
num.forEach(f);

Is the same as:
function f(item, index) {}
var num = [3, 2, 1];
for(var i=0; i<num.length; i++)
f(num[i], i);

In both cases, f is called 3 times. It is called with:
item index
3 0
2 1
1 2