JavaScript RegExp Objects
The RegExp Object
In JavaScript, RegExp is a regular expression object with predefined properties and methods.
Using test()
The test() method is a RegExp expression method.
It searches a string for a pattern, and returns true or false, depending on the result.
The following example searches a string for the character "e":
Example
const pattern = /e/;
pattern.test("The best things in life are free!");
Since there is an "e" in the string, the output of the code above will be:
true
You don't have to put the regular expression in a variable first. The two lines above can be shortened to one:
/e/.test("The best things in life are free!");
Using exec()
The exec() method is a RegExp expression method.
It searches a string for a specified pattern, and returns the found text as an object.
If no match is found, it returns an empty (null) object.
The following example searches a string for the character "e":
The RegExp.escape() Method
The RegExp.escape() method returns string where characters that belongs
to the regular expression syntax are escaped.
This makes it possible to treat characters like +, *, ?, ^, $, (, ), [, ], {, }, |, and \ literally, and not as part of a regular expression.
Example
Create a regular expression that matches the string "[*]":
// Escape a text for to use as a regular expression
const safe = RegExp.escape("[*]";
// Build a new reglar expression
const regex = new RegExp(safe);
// Text to replace within
const oldText = "[*] is a web school.";
// Perform the replace
const newText = oldText.match(regex, "W3Schools");
Try it Yourself »
RegExp.escape() is supported all in modern browsers since May 2025:
| Chrome 136 | Edge 136 | Firefox 134 | Safari 18.2 | Opera 121 |
| Apr 2025 | May 2025 | Jan 2025 | Des 2024 | Jun 2025 |
