JS: RegExp.prototype

RegExp.prototype is the value of the property key "prototype" of the function RegExp.

[see JS: RegExp Object]

console.log(
 RegExp.hasOwnProperty ( "prototype" ) ); // true

Type

Type of RegExp.prototype is object.

[see JS: Value Types]

// type of RegExp.prototype
console.log (
 typeof RegExp.prototype === "object" ); // true

console.log (
 Object.prototype.toString.call( RegExp.prototype ) === "[object Object]" ) // true

Parent

Parent of RegExp.prototype is Object.prototype.

// parent of RegExp.prototype
console.log (
 Object.getPrototypeOf ( RegExp.prototype ) === Object.prototype ); // true

[see JS: Prototype and Inheritance]

Purpose

Purpose of RegExp.prototype is to provide methods and properties useful for all regexp instances.

RegExp.prototype is the parent of all RegExp instances.

console.log (
 Object.getPrototypeOf ( /abc/ ) === RegExp.prototype ); // true

Properties

Function Properties

1. RegExp.prototype.test
2. RegExp.prototype.exec
3. RegExp.prototype.toString ( )
4. RegExp.prototype [ Symbol.match ] ES2015
5. RegExp.prototype [ Symbol.replace ] ES2015
6. RegExp.prototype [ Symbol.search ] ES2015
7. RegExp.prototype [ Symbol.split ] ES2015

Value Properties

1. RegExp.prototype.source
2. RegExp.prototype.global
3. RegExp.prototype.ignoreCase
4. RegExp.prototype.multiline
5. RegExp.prototype.lastIndex
6. RegExp.prototype.flags ES2015
7. RegExp.prototype.sticky ES2015
8. RegExp.prototype.unicode ES2015

---

Function Properties

RegExp.prototype [ Symbol.match ]

ECMAScript® 2016 Language Specification#sec-regexp.prototype-@@match

RegExp.prototype [ Symbol.replace ]

ECMAScript® 2016 Language Specification#sec-regexp.prototype-@@replace

RegExp.prototype [ Symbol.search ]

ECMAScript® 2016 Language Specification#sec-regexp.prototype-@@search

RegExp.prototype [ Symbol.split ]

ECMAScript® 2016 Language Specification#sec-regexp.prototype-@@split

Value Properties

Property	Read Only	Meaning
source	read only	the regex pattern as string.
global	read only	true if there's the global flag g in regex.
ignoreCase	read only	true if there's the ignore case flag i in regex.
multiline	read only	true if there's the multi-line flag m in regex.
unicode	read only	true if there's the unicode flag u in regex. ES2015
sticky	read only	true if there's the sticky flag y in regex. ES2015
flags	read only	Returns a string of all used flags. e.g. "gimuy" ES2015

Property	Read Only	Meaning
lastIndex	read/write	When global flag g is used, the value is the position of end of last match. Next invocation of the method with the same RegExp object will start from here. (you may want to reset this to 0 in a loop.) When global flag is not used, this value is always 0.

[see JS: RegExp Syntax]

Example:

// example of RegExp.prototype value properties

const txt = "love cats";

const regex = new RegExp("cat", "ig");

const result = regex.exec(txt);

// print RegExp properties
console.log ( regex.source === "cat"); // true
console.log ( regex.global);     // true
console.log ( regex.ignoreCase); // true
console.log ( regex.multiline);  // false
console.log ( regex.flags === "gi"); // true

console.log ( regex.lastIndex); // 8

// print result
console.log ( result); // [ 'cat', index: 5, input: 'love cats' ]

RegExp Result Object Properties

Property	Meaning
index	the beginning position of first occurrence.
input	the input string.

// example of RegExp result properties

const myText = 'a x1 X2 c';

const myRe = new RegExp('\\w\\d+', "ig");

const myResult = myRe.exec(myText);

// print result properties

console.log ( myResult.index); // 2
console.log ( myResult.input); // a x1 X2 c

Reference

ECMAScript® 2016 Language Specification#sec-regexp.prototype