RightPad

Function RightPad( S : string; Ch : Char; Len : Integer) : string

Example

procedure ScriptEvent(var Value: variant);
begin
  Value := RightPad('42', '0', 5); // 00042
end;

Usage

RightPad prepends a chosen character until text reaches a minimum length, despite the function's right-padding name.

Parameters and return value

Item	Meaning
S	Text to retain. It is passed by value and not mutated.
Ch	Character prepended when padding is needed.
Len	Minimum result length in Velox string code units.
Result	S unchanged when Len <= Length(S); otherwise left padding followed by S.

Important behavior and quirks

• The name does not describe the implemented direction. For conventional space padding, PadL also pads on the left and PadR pads on the right.
• LeftPad contains the reciprocal defect and appends its padding on the right.
• The function never truncates text.
• Zero or negative Len returns S unchanged.
• A NUL padding character creates embedded NULs before the visible text and can confuse pointer-based consumers.
• This is raw text padding. With a signed number such as -42, zero padding produces 00-42, not -0042.

Additional Technical Info

RightPad currently pads on the left. When S is shorter than Len, it returns StringOfChar(Ch, Len - Length(S)) + S. The public name is therefore directionally reversed.

The example is fictional and source-reviewed only.

Performance and concurrency

The helper allocates the padding and concatenated result. It reads no shared state.

External references

• Embarcadero DocWiki: System.StringOfChar
• Free Pascal: System.StringOfChar

Created 2026-07-15