match substring javascript code example

Example 1: javascript string contains

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

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

Example 2: string contains in javascript

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

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

Example 3: javascript regex example match

//Declare Reg using slash
let reg = /abc/
//Declare using class, useful for buil a RegExp from a variable
reg = new RegExp('abc')

//Option you must know: i -> Not case sensitive, g -> match all the string
let str = 'Abc abc abc'
str.match(/abc/) //Array(1) ["abc"] match only the first and return
str.match(/abc/g) //Array(2) ["abc","abc"] match all
str.match(/abc/i) //Array(1) ["Abc"] not case sensitive
str.match(/abc/ig) //Array(3) ["Abc","abc","abc"]
//the equivalent with new RegExp is
str.match('abc', 'ig') //Array(3) ["Abc","abc","abc"]

Example 4: js string to regex

const regex = new RegExp('https:\\/\\/\\w*\\.\\w*.*', 'g');