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RegExMatch

Function RegExMatch( const ARegExpr, AInputStr : string) : boolean

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := RegExMatch('^[A-Z]{2}-[0-9]{4}$', 'NZ-2048'); // True
end;

Usage​

RegExMatch reports whether a Velox regular expression finds any non-empty match within an input string.

Parameters

ParameterMeaning
ARegExprVelox/PCRE regular-expression pattern.
AInputStrString searched by the pattern.

Return value

True if TRegEx.IsMatch(AInputStr, ARegExpr) succeeds; otherwise False.

Important behavior and quirks

  • Parameter order is pattern first, input second, although Velox's method receives input first.
  • The default options are used. In the installed runtime these include roNotEmpty, so a pattern does not report success solely for an empty match.
  • Matching is case-sensitive unless the expression supplies a supported inline case-insensitive option.
  • RegExMatch('cat', 'concatenate') is True; use ^cat$ when the entire input must match.
  • A Boolean False means no qualifying match, not that the pattern was invalid.

Additional Technical Info​

RegExMatch returns whether ARegExpr finds a non-empty match in AInputStr. The function searches anywhere in the input unless the pattern includes anchors such as ^ and $.

The example is fictional and source-reviewed only.

Errors, performance and concurrency

Invalid syntax raises a regular-expression exception rather than returning False. Each call constructs and prepares a new regex object. Expressions with catastrophic backtracking can consume disproportionate CPU; inputs and patterns from untrusted sources require external size, complexity or timeout controls. The per-call object is local and does not intentionally mutate Velox state.

External references

Created 2026-07-15