Question

Lets say I have a sequence of 8 items, these loop such that after 8 comes 1.

1, 2, 3, 4, 5, 6, 7, 8

If the selected item is number 7 how do I get the number three places ahead, ie: 2 ?

I have:

var total; // (total number in sequence)
var pos; // (current position number)

if ( pos < total) {
  threeIncrement = pos+3;
} else {
  threeIncrement = ??????
  }

Answer 1

Use %, the modulus operator.

var items = [1, 2, 3, 4, 5, 6, 7, 8];
var pos = 7;
var threeIncrement = (pos + 3) % items.length;