string contains javascript substring code example

Example 1: javascript contains substring

var str = "We got a poop cleanup on isle 4.";
if(str.indexOf("poop") !== -1){
	alert("Not again");
}
//use indexOf (it returns position of substring or -1 if not found)

Example 2: includes in javascript

var colors = ['yellow', 'red', 'pink'];
var string = 'yellow and red are pretty cool';

// outputs false
console.log(colors.include('blue');
// outputs true
console.log(string.includes('yellow');