catch forEach last iteration

Question

arr = [1,2,3]; arr.forEach(function(i){ // last iteration }); 

How to catch when the loop ending? I can do if(i == 3) but I might don't know what is the number of my array.

Answer 1

Updated answer for ES6+ is here.

---

arr = [1, 2, 3];   arr.forEach(function(i, idx, array){    if (idx === array.length - 1){         console.log("Last callback call at index " + idx + " with value " + i );     } }); 

would output:

Last callback call at index 2 with value 3 

The way this works is testing arr.length against the current index of the array, passed to the callback function.