How do I test this regex in JavaScript and TypeScript?

Use regex.test(): const regex = /\/\*[\s\S]*?\*\/|\/\/.*/g; const isValid = regex.test(inputString);

What is an example of a matching and non-matching string?

A valid matching string is "/* Multi-line comment block */ // single line comment". A non-matching string is "const x = 10 / 2;".

Is this regex safe from ReDoS (Catastrophic Backtracking)?

Yes, this pattern is optimized for linear execution time and safe for browser-side validation without locking up the UI thread.

HomeRegex LibraryC-Style Code Comment Regex

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C-Style Code Comment Regex

Matches single-line (//) and multi-line (/* ... */) code comments across JavaScript, C, Java, Go, and PHP.

Regular Expression Pattern:

/\/\*[\s\S]*?\*\/|\/\/.*/g

Valid Match Example:

/* Multi-line comment block */ // single line comment

Invalid / Non-Match Example:

const x = 10 / 2;

Regex Syntax Breakdown & Explanation

•\/\*[\s\S]*?\*\/ : Non-greedy match of multi-line comment blocks
•| : Logical OR operator
•\/\/.* : Single line comment from double slash to end of line

Implementation in Popular Languages

JavaScript / TypeScript

const regex = /\/\*[\s\S]*?\*\/|\/\/.*/g;
const isValid = regex.test("/* Multi-line comment block */ // single line comment");
console.log(isValid); // true

Python (re)

import re

pattern = r"\/\*[\s\S]*?\*\/|\/\/.*"
match = re.match(pattern, "/* Multi-line comment block */ // single line comment")
print(bool(match)) # True

Go (regexp)

package main
import (
  "fmt"
  "regexp"
)

func main() {
  re := regexp.MustCompile(`\/\*[\s\S]*?\*\/|\/\/.*`)
  fmt.Println(re.MatchString("/* Multi-line comment block */ // single line comment"))
}

Frequently Asked Questions

Everything you need to know regarding specifications, syntax, and security best practices.

The regular expression pattern is /\/\*[\s\S]*?\*\/|\/\/.*/g. Matches single-line (//) and multi-line (/* ... */) code comments across JavaScript, C, Java, Go, and PHP.