How to check whether a string contains a substring in JavaScript?
Asked October 7, 2020
Usually I would expect a String.contains() method, but there doesn't seem to be one.
What is a reasonable way to check for this?
Answer
ECMAScript 6 introduced String.prototype.includes:
const string = "foo";
const substring = "oo";
console.log(string.includes(substring));includes doesn’t have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns -1 when a substring cannot be found:
var string = "foo";
var substring = "oo";
console.log(string.indexOf(substring) !== -1)