Text Processingflags: gm

JavaScript Variable Declaration

Match JavaScript / TypeScript variable declarations (`var`, `let`, `const`), capturing the keyword and identifier name.

Try it in RegexPro →

Available in

JSSupported

JavaScript / ECMAScript

Browser-native RegExp. Default if you don't pick.

PYSupported

Python (re)

CPython stdlib `re`. Unicode-aware `\w` and `\d` by default.

GOSupported

Go (RE2)

Linear-time matching. No backreferences or lookarounds.

Pattern

regexengine-agnostic
\b(var|let|const)\s+([a-zA-Z_$][\w$]*)\s*(?:=|;|$)   (flags: gm)

Raw source: \b(var|let|const)\s+([a-zA-Z_$][\w$]*)\s*(?:=|;|$)

How it works

\b(var|let|const) captures the declaration keyword at a word boundary. \s+ requires whitespace. ([a-zA-Z_$][\w$]*) captures a valid JS identifier (starts with letter, underscore, or $). \s*(?:=|;|$) matches the assignment or terminator so we don't mis-match function parameters.

Examples

Input

const x = 1;\nlet name = "alice";\nvar count;

Matches

  • const x =
  • let name =
  • var count;

Input

const { a, b } = obj

Matches

  • const { a, b } =

Input

// no decl

No match

—

Common use cases

  • •AST-free quick code analysis
  • •Codemods (var → let / const conversions)
  • •Linting for var-usage in modern codebases
  • •Documentation / refactoring tooling
←PreviousJSON Log Line (Single-Line Object)
All patterns