JavaScript: RegExp.prototype

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

〔►see JavaScript: RegExp Object〕

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

Type of RegExp.prototype is object.

〔►see JavaScript: Data Types〕

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

Parent of RegExp.prototype is Object.prototype.

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

〔►see JavaScript: Prototype and Inheritance〕

RegExp.prototype is the parent of all RegExp instances.

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

The purpose of RegExp.prototype object is to provides methods and properties useful for all regexp instances.

Properties

Function Properties

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

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Function Properties

RegExp.prototype.test

Returns true or false.

〔►see JavaScript: RegExp.prototype.test〕

RegExp.prototype.exec

Returns a array of captured groups.

〔►see JavaScript: RegExp.prototype.exec〕

RegExp.prototype [ Symbol.match ] ( str ) (ES2015)

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

RegExp.prototype [ Symbol.replace ] ( str, replaceValue ) (ES2015)

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

RegExp.prototype [ Symbol.search ] ( str ) (ES2015)

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

RegExp.prototype [ Symbol.split ] ( str, limit ) (ES2015)

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

Value Properties

Property	Read Only	Meaning
source	read only	the regex pattern 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 JavaScript: RegExp Syntax〕

Example:

// example of RegExp.prototype value properties

var txt = 'a x1 x2 c';

var regex = new RegExp('x2', "ig");

var result = regex.exec(txt);

// print RegExp properties

console.log ( regex.source);    // x2

console.log ( regex.global);     // true
console.log ( regex.ignoreCase); // true
console.log ( regex.multiline);  // false
console.log ( regex.flags); // "gi"

console.log ( regex.lastIndex); // 7

// print result
console.log ( result); // [ 'x2', index: 5, input: 'a x1 x2 c' ]

RegExp Result Object Properties

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

// example of RegExp result properties

var myText = 'a x1 X2 c';

var myRE = new RegExp('\\w\\d+', "ig");

var 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