JAVASCRIPT

regular expression javascript

// Tests website Regular Expression against document.location (current page url)
if (/^https://example.com/$/.exec(document.location)){
	console.log("Look mam, I can regex!");
}

what is regular expression in javascript

let re = /ol/, 
Characters , ., cX, d, D, f, 
, 
, s, S, 	, v, w, W, , xhh, uhhhh, uhhhhh, []	
Assertions 	^, $, x(?=y), x(?!y), (?<=y)x, (?<!y)x, , B
Groups 		(x), (?:x), (?<Name>x), x|y, [xyz], [^xyz], Number	
Quantifiers *, +, ?, x{n}, x{n,}, x{n,m}
Unicode p{UnicodeProperty}, P{UnicodeProperty}	 property escapes
let defaults = new RegExp('compiled'); 
defaults = { dotAll: false, flags: "", global: false, ignoreCase: false, falselastIndex: 0, multiline: false, source: "abc", sticky: false, unicode: false}

regular expression javascript

console.log(/'d+'/.test("'123'"));
// → true
console.log(/'d+'/.test("''"));
// → false
console.log(/'d*'/.test("'123'"));
// → true
console.log(/'d*'/.test("''"));
// → true

javascript regular expression

var regularExpression = /^(?=.*[0-9])(?=.*[!@#$%^&*])[a-zA-Z0-9!@#$%^&*]{6,16}$/;

Regular expression javascript

^.*(?=.{8,})(?=.*[a-zA-Z])(?=.*d)(?=.*[!#$%&? "]).*$

---

^.*              : Start
(?=.{8,})        : Length
(?=.*[a-zA-Z])   : Letters
(?=.*d)         : Digits
(?=.*[!#$%&? "]) : Special characters
.*$              : End

regular function JavaScript

//! Button Click Event
//! regular function
document.querySelector("button").addEventListener('click', handlClick);

function handlClick() {
    alert("I got clicked!")//just to show it works
  
  //what to do when click detected
}

//!anonymous function
document.querySelector("button").addEventListener('click',function handlClick() {
    alert("I got clicked!")//just to show it works
  
  //what to do when click detected
});

JavaScript Regular Expression Methods

const regex1 = /^ab/;
const regex2 = new Regexp('/^ab/');