How to Use match Method in JavaScript: Syntax and Examples

The match() method in JavaScript is used on strings to find matches based on a regular expression. It returns an array of matches or null if no match is found. You use it by calling string.match(regex) where regex is a regular expression pattern.

Syntax

The match() method is called on a string and takes one argument: a regular expression (RegExp object). It returns an array of matches or null if no matches are found.

• string: The text you want to search.
• regex: The pattern to find, written as a regular expression.
• Return value: An array of matches or null.

javascript

string.match(regex)

Example

This example shows how to find all words starting with 'a' in a sentence using match() with a global regular expression.

javascript

const text = "Apples and apricots are amazing.";
const matches = text.match(/a\w*/gi);
console.log(matches);

Output

["Apples", "and", "apricots", "are", "amazing"]

Common Pitfalls

One common mistake is forgetting the global flag g in the regular expression, which causes match() to return only the first match instead of all matches. Another is using match() on a string without a regular expression, which may not work as expected.

javascript

const text = "Hello hello hello";

// Wrong: missing global flag
const firstMatch = text.match(/hello/i);
console.log(firstMatch); // Outputs only first match

// Right: with global flag
const allMatches = text.match(/hello/gi);
console.log(allMatches); // Outputs all matches

Output

["Hello"]
["Hello", "hello", "hello"]

Quick Reference

Feature	Description
Input	A string to search
Argument	A regular expression (e.g., /pattern/g)
Return	Array of matches or null if none
Global flag (g)	Returns all matches, not just first
Case-insensitive flag (i)	Matches ignoring case

Key Takeaways

Use match() on strings with a regular expression to find matches.

Include the global flag g to get all matches, not just the first.

If no matches are found, match() returns null.

Regular expressions control what match() looks for in the string.

Without a regular expression, match() may not behave as expected.