Compare part of string in JavaScript

Question

How do I compare a part of a string - for example if I want to compare if string A is part of string B. I would like to find out this: When string A = \"abcd\"

Answer 1

Javascript ES6/ES2015 has String.includes(), which has nearly all browser compatibility except for IE. (But what else is new?)

let string = "abcdef";
string.includes("abcd"); //true
string.includes("aBc"); //false - .includes() is case sensitive