JavaScript Comments Regex

Replacement

Regular expression

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

Pattern breakdown

Part	Meaning
`Anchor or context`	Use anchors when you need whole-string validation.
`Main token`	The core token sequence describes the accepted text shape.
`Character class`	Character classes limit which characters are valid.
`Quantifier`	Quantifiers control how many characters or groups are accepted.
`Flags`	Use language-specific flags such as i, m, or u only when needed.

Should match

// TODO
//TODO

Should not match

const x = 1
not matching sample
// TODO invalid
const x = 1// TODO

Test cases

Input	Expected	Why it matters
`// TODO`	Match	Representative valid input for this pattern.
`//TODO`	Match	Representative valid input for this pattern.
`const x = 1`	No match	Common invalid or boundary input.
`(empty string)`	No match	Common invalid or boundary input.
`not matching sample`	No match	Common invalid or boundary input.
`// TODO invalid`	No match	Common invalid or boundary input.
`const x = 1// TODO`	No match	Common invalid or boundary input.

JavaScript

const re = //\*[\s\S]*?\*/|//.*/;
re.test(input);

Python

import re
bool(re.search(r"/\*[\s\S]*?\*/|//.*", text))

PHP

$ok = preg_match('/\/\*[\s\S]*?\*\/|\/\/.*/', $value) === 1;

Java

Pattern pattern = Pattern.compile("/\\*[\\s\\S]*?\\*/|//.*");
pattern.matcher(value).find();

Go

re := regexp.MustCompile(`/\*[\s\S]*?\*/|//.*`)
ok := re.MatchString(value)

Notes and production use

JavaScript Comments regex is useful as a practical starting point. Test it against your real input, avoid using it as the only security control, and prefer a parser when the format has complex grammar.

Performance tip: avoid running complex regular expressions repeatedly on very large untrusted strings without limits. Prefer anchored validation patterns, cap input length before matching, and use a parser when the target format has nested grammar.

JavaScript Comments