javascript string dosent includes code example

Example 1: javascript string contains

var string = "foo",
    substring = "oo";

console.log(string.includes(substring));

Example 2: javascript string includes

const s = 'I am going to become a FULL STACK JS Dev with Coderslang';

console.log(s.includes('FULL STACK'));     // true
console.log(s.includes('cheeseburger'));   // false