how to know if there's a string inside a string code example

Example 1: How find a specific character in js

var word = "This is how you locate a word in a string";
var n = word.includes("word");

Example 2: js check if string contains character

"FooBar".includes("oo"); // true

"FooBar".includes("foo"); // false

"FooBar".includes("oo", 2); // false