search string javascript

1var str = "This is a test sentence";
2var hasTest = str.includes("test");
3
4if(hasTest == true){
5	//do a thing 
6}

1//regular indexof
2let a = 'asbdais sbbdias isajdij';
3a.indexOf('ias');
4// with regex:
5let a = 'asbdais sbbdias isajdij';
6a.search(/ias/g);

1var string = "Hello world!";
2var n = string.search("w"); //now n equals 6

1"I love cats".indexOf("cat") //returns 7, the position of "cat"