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Modulo

Another arithmetic operator is modulo. It calculates the remainder of a division and is represented by %.
var x = 7 % 2;
var y = 20 % 3;
7 divided by 2 is 3 with remainder 1. x is 1.
20 divided by 3 is 6 with remainder 2. y is 2.

Exercise

Write a function onesDigit that takes a natural number and returns the ones digit of that number. onesDigit(2674) should return 4.
var onesDigit = function(n) {
// Use modulo 10.  
};
var onesDigit = function(n) {
  return n % 10;
};