Pattern

Regex for Block comment (/ /)

C-style multi-line comment.

The Block comment (/* */) regex is \/\*[\s\S]*?\*\/ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

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

Open in explainer → Download cheat sheet ↓

Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`\/`	literal “/”
`\*`	literal “*”
`[\s\S]*?`	zero or more (lazy — as few as possible): any of: whitespace, non-whitespace
`\*`	literal “*”
`\/`	literal “/”

About this pattern

Developer-oriented patterns help with code analysis, log parsing, and data transformation. Use these in build scripts, CI tools, and code review utilities.

Quick usage in different languages

This exact pattern — with the correct escaping and idioms for each language:

JavaScript: /\\/\*[\s\S]*?\*\\//.test(value)
Python: re.match(r"\/\*[\s\S]*?\*\/", value)
Java: Pattern.compile("\\/\\*[\\s\\S]*?\\*\\/").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"\/\*[\s\S]*?\*\/")
Go: regexp.MustCompile(`\/\*[\s\S]*?\*\/`).MatchString(value)
Ruby: /\\/\*[\s\S]*?\*\\//.match?(value)
PHP: preg_match('~\/\*[\s\S]*?\*\/~', $value)

The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.

Common pitfalls

Not anchored. Without ^ and $ this can match a substring anywhere in the input — add anchors if you need the whole value to conform.
Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the block comment (/* */) against a source of truth (database, API, or checksum) where it matters.

Related patterns

More patterns in the Developer category:

Regex for Block comment (/* */)