RegExp Quantifiers

Regular Expression (Regex) quantifiers define how many times the preceding character, group, or character class must occur in a string. They control the boundaries of your match...

Regular Expression (Regex) quantifiers define how many times the preceding character, group, or character class must occur in a string. They control the boundaries of your matches, allowing patterns to be flexible.

// Match at least one zero const pattern = /0+/;

JavaScript RexExp Quantifiers

Revised July 2025

Code	Description
x+	Matches at least one x
x*	Matches zero or more occurrences of x
x?	Matches zero or one occurrences of x
x{n}	Matches n occurences of x
x{n,m}	Matches from n to m occurences of x
x{n,}	Matches n or more occurences of x

RegExp + Quantifier

x+ matches matches at least one x.

Example

Example Code

javascript

Try it Yourself

let text = "Hellooo World! Hello EA Academy!";

const pattern = /o+/g;

let result = text.match(pattern);

RegExp * Quantifier

x matches zero or more occurrences of x*.

Example

Example Code

javascript

Try it Yourself

let text = "Hellooo World! Hello EA Academy!";

const pattern = /lo*/g;

let result = text.match(pattern);

RegExp ? Quantifier

x? matches zero or one occurrences of x.

Example

Example Code

javascript

Try it Yourself

let text = "1, 100 or 1000?";

const pattern = /10?/g;

let result = text.match(pattern);

RegExp {n} Quantifier

x{n} matches n occurences of x.

Example

Example Code

javascript

Try it Yourself

let text = "100, 1000 or 10000?";

let pattern = /\d{4}/g;

let result = text.match(pattern);

RegExp {n,m} Quantifier

x{n,m} matches from n to m occurences of x.

Example

Example Code

javascript

Try it Yourself

let text = "100, 1000 or 10000?";

let pattern = /\d{3,4}/g;

let result = text.match(pattern);

RegExp {n,} Quantifier

x{n,} matches n or more occurences of x.

Example

Example Code

javascript

Try it Yourself

let text = "100, 1000 or 10000?";

let pattern = /\d{3,}/g;

let result = text.match(pattern);

Regular Expression Methods

Regular Expression Search and Replace can be done with different methods.

These are the most common:

String Methods

Method	Description
match(regex)	Returns an Array of results
matchAll(regex)	Returns an Iterator of results
replace(regex)	Returns a new String
replaceAll(regex)	Returns a new String
search(regex)	Returns the index of the first match
split(regex)	Returns an Array of results

RegExp Methods

Method	Description
regex.exec()	Returns an Iterator of results
regex.test()	Returns true or false

See Also: > JavaScript RegExp Tutorial > JavaScript RegExp Flags > JavaScript RegExp Character Classes > JavaScript RegExp Meta Characters > JavaScript RegExp Assertions > JavaScript RegExp Groups > JavaScript RegExp Patterns > JavaScript RegExp Objects > JavaScript RegExp Methods