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vxTryStrToCurr

function vxTryStrToCurr(
  const S: string;
  out Value: Currency): Boolean;

Example​

procedure ScriptEvent(var Value: variant);
var
  Amount: Currency;
begin
  if vxTryStrToCurr('125', Amount) then
    Value := Amount
  else
    Value := Null;
end;

Usage​

vxTryStrToCurr attempts a system-locale Currency conversion and reports whether the output value is valid.

Parameters

NameTypeDescription
Sstring, constOptional sign, decimal/scientific digits and the Windows system decimal separator, with optional surrounding ASCII spaces.
ValueCurrency, outReceives the four-decimal fixed-point result on success. Treat it as undefined/unusable when the function returns False.

Returns

True when the entire token is valid and in Currency range; otherwise False.

Behaviour

Use the Boolean as the validity contract. Symbols, grouping characters, accounting parentheses, the wrong decimal separator, malformed exponents, extra characters and range overflow return False.

Errors

Ordinary parse and range failures return False. The function does not catch locale acquisition, allocation or unexpected runtime exceptions.

Usage notes

This is the preferred member of the Currency parsing family when invalid input is expected and must be handled explicitly. It does not validate decorated money formats; normalise those according to the source specification first.

Additional Technical Info​

vxTryStrToCurr attempts to parse complete system-locale numeric text into Delphi Currency. It returns a Boolean instead of raising for ordinary conversion failure and writes a usable Value only when that Boolean is True.

The fictional integer example is source-reviewed and not executed by the documentation workflow.

Implementation

The scripting import maps the function to vxFormats.vxTryStrToCurr. The wrapper creates TFormatSettings.Create(LOCALE_SYSTEM_DEFAULT) and invokes System.SysUtils.TryStrToCurr(S, Value, AFormatSettings). The installed Delphi overload directly returns its Currency TextToFloat result.

That terminal parses decimal/scientific syntax, rounds to four places with ties to even, and rejects results outside Currency's scaled signed-64-bit range.

Edge cases and quirks

  • The parser accepts a signed exponent even though the destination is fixed-point Currency.
  • Excess fractional precision is rounded rather than treated as invalid. Exact half-way cases round to an even fourth-decimal digit.
  • NAN, INF and -INF return False.
  • Leading/trailing ASCII spaces are accepted; arbitrary internal spaces are not.
  • Failure does not supply a defined business value. Do not read, log or persist Value unless the Boolean is True, even if a particular build appears to leave a prior/intermediate value there.
  • The source locale is Windows LOCALE_SYSTEM_DEFAULT, not the current user. Identical text can succeed on one Velox host and fail on another.
  • The DocWiki description for this routine contains legacy wording about returning Default; the declaration and installed source show the actual out Value/Boolean contract documented here.

Side effects

On success the caller's output variable is written. No persistent product state is changed.

Performance and concurrency

Parsing is linear in source length. The local settings record isolates the call from Delphi global-format mutations; system-locale changes can affect subsequent calls.

Related entries

  • vxStrToCurr raises on failure.
  • vxStrToCurrDef returns a caller-supplied fallback and cannot distinguish fallback collision.
  • vxTryStrToFloat has a floating Extended destination and accepts floating special values.

External references

Created 2026-07-15