Pattern

Regex for Quoted string

Match either single- or double-quoted strings.

The Quoted string regex is (["\'])(?:(?=(\\?))\2.)*?\1 — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

(["\'])(?:(?=(\\?))\2.)*?\1

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What it matches

"hello"
'world'
"escape \" inside"

What it doesn't match

no quotes
"unclosed

Notes & gotchas

Matches paired quotes (same kind on both sides) and handles escaped quotes inside. For simple needs, "[^"]*" is faster but doesn't handle escapes.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

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Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`(`	start of a capturing group
`["\']`	any of: “"”, “'”
`)`	end of group
`(?:`	start of a non-capturing group
`(?=`	start of a positive lookahead — followed by
`(`	start of a capturing group
`\\?`	optional (zero or one): literal “\”
`)`	end of group
`)`	end of group
`\2`	backreference to group 2
`.`	any character (except newline)
`)*?`	end of group, zero or more (lazy — as few as possible)
`\1`	backreference to group 1

About this pattern

Number patterns appear constantly in form validation, log parsing, and data extraction. Regex is great for matching the shape but limited for semantic checks (range validation, mathematical constraints).

Quick usage in different languages

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

JavaScript: /(["\'])(?:(?=(\\?))\2.)*?\1/.test(value)
Python: re.match(r"""(["\'])(?:(?=(\\?))\2.)*?\1""", value)
Java: Pattern.compile("([\"\\'])(?:(?=(\\\\?))\\2.)*?\\1").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"([""\'])(?:(?=(\\?))\2.)*?\1")
Go: regexp.MustCompile(`(["\'])(?:(?=(\\?))\2.)*?\1`).MatchString(value)
Ruby: /(["\'])(?:(?=(\\?))\2.)*?\1/.match?(value)
PHP: preg_match('~(["\'])(?:(?=(\\?))\2.)*?\1~', $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 quoted string against a source of truth (database, API, or checksum) where it matters.

Related patterns

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