JS: Regex Find/Replace

By Xah Lee. Date: . Last updated: .

Regex means Regular Expression. It is used to check if a string contains certain pattern, or extract the pattern, or replace it with other string. For example, extract email addresses in a text file.

For basic tutorial, see JS: RegExp Tutorial

There are 2 ways to use RegExp in JavaScript:

Following is a summary of the different methods.



Get the index of first char of matched string.

[see JS: String.prototype.search]


Get a array of captured groups, or, get array of all occurrences.

[see JS: String.prototype.match]



Get a new string.

[see JS: String.prototype.replace]



Return true or false.

[JS: RegExp.prototype.test]



Return a array of captured groups.

[JS: RegExp.prototype.exec]

RegExp Topic

  1. JS: RegExp Tutorial
  2. JS: RegExp Syntax
  3. JS: Regex Find/Replace
  4. JS: RegExp Object
  5. JS: RegExp Constructor
  6. JS: RegExp.prototype

JS String

  1. String Overview
  2. Template String
  3. Char, Code Unit, Code Point
  4. String Escape Sequence
  5. Unicode Escape Sequence
  6. String to Number
  7. Encode URL, Escape String
  8. Format Number
  9. Source Code Encoding
  10. Allowed Characters in Identifier
  11. String Object
  12. String.prototype
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