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RemoveChars

Function RemoveChars( const s : string; const aCharsToRemove : string) : string

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := RemoveChars('INV-2026/0042', '-/'); // INV20260042
end;

Usage​

RemoveChars removes every occurrence of each character listed in a string by applying repeated case-sensitive replace-all passes.

Parameters and return value

ItemMeaning
sSource string. It is not mutated.
aCharsToRemoveString whose individual characters are to be removed. It is not interpreted as a substring or regex.
ResultA new string with the selected characters removed.

Important behavior and quirks

  • An empty removal list returns the original text.
  • Duplicate characters in the removal list do not change the result, but cause redundant full-string passes.
  • RemoveChars('AaA', 'A') returns a; lowercase and uppercase are distinct.
  • The routine removes UTF-16 code units, not user-perceived grapheme clusters. Supplying one half of a surrogate pair can create invalid Unicode text.
  • Unlike RemoveChars2, Velox is length-based and does not stop merely because the source contains an embedded NUL.

Additional Technical Info​

RemoveChars returns s after removing every occurrence of every code unit listed in aCharsToRemove. The removal list is a string, so each of its positions is processed independently and in order.

The example is fictional and source-reviewed only.

How it works

Velox starts with Result := s. For each one-based position in aCharsToRemove, it runs Delphi StringReplace(Result, aCharsToRemove[i], '', [rfReplaceAll]). Search is case-sensitive because rfIgnoreCase is not supplied.

Performance and concurrency

The function performs one complete replace-all operation per removal-list position and allocates intermediate strings. For a long source or large removal list, a set-based single pass can be substantially cheaper. It uses no mutable Velox state.

External references

Created 2026-07-15