AddQuotes
Function AddQuotes(const aValue: string; aChar: Char): string
Example
procedure ScriptEvent(var Value: variant);
begin
Value := AddQuotes('O''Brien', ''''); // 'O''Brien' enclosed in apostrophes
end;
Usage
AddQuotes wraps text in a chosen quote character and doubles that character unless both outer quotes already exist.
Parameters
| Name | Type | Description |
|---|---|---|
aValue | string | Text to inspect, escape and enclose. |
aChar | Char | Character used for both the outer pair and embedded-character doubling. It need not be an apostrophe or quotation mark. |
Return value
Returns either the original already-wrapped value or a new string formed as:
aChar + ReplaceEvery(aValue, aChar, aChar + aChar) + aChar
An empty value therefore returns two copies of aChar.
Additional Technical Info
AddQuotes encloses a string in the supplied character. Before adding the outer pair, it doubles every occurrence of that character so quote-delimited text can represent an embedded quote. If the value already begins and ends with the character, the function returns it unchanged.
The example is fictional and source-reviewed only.
Implementation and exact edge behaviour
The Velox helper first tests aValue[1] and aValue[Length(aValue)], with an explicit empty-string guard. Only when both ends equal aChar does it bypass all processing. It does not inspect whether the inner text is correctly escaped.
Otherwise it calls Delphi StringReplace with rfReplaceAll and rfIgnoreCase, then adds the outer characters. Case-insensitive matching has no practical effect when the old pattern is a single punctuation quote, but can matter if a letter is supplied as aChar.
Partially quoted input is not normalised. For example, an input that has only a leading apostrophe has that existing apostrophe doubled before a new leading and trailing apostrophe are added. Validate or strip one-sided delimiters before calling the function.
This is a mechanical quoting helper, not a general SQL, CSV, JSON or Pascal string encoder. It does not apply the complete escaping rules of those formats. Use the format-specific serializer or parameter binding at a trust boundary.
Related entries
StripQuotesremoves one recognised outer quote pair.SafeSQLperforms Velox's separate SQL-text escaping operation; database parameters remain preferable.
External references
Created 2026-07-15