not includes in javascript code example

Example 1: javascript string contains

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

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

Example 2: js string contais

const string = "foo";
const substring = "oo";

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

Example 3: javascript string includes

'Blue Whale'.includes('blue')  // returns false

Example 4: .includes( string

var str = "Hello world, welcome to the universe.";
var n = str.includes("world");

Example 5: string.contains javascript

var str = "We got a poop cleanup on isle 4.";
if(str.indexOf("poop") !== -1){
	alert("Not again");
}

Example 6: javascript includes method

arr.includes(searchElement[, fromIndex = 0])