StrToIntDef

function StrToIntDef(S: string; def: LongInt): LongInt;

Example

procedure ScriptEvent(var Value: variant);
begin
  Value := StrToIntDef('not-an-integer', 0);  // 0
end;

Usage

StrToIntDef parses a signed LongInt through Velox scripting, returning a supplied value when parsing fails.

Parameters

Name	Type	Description
S	string	Signed integer text for a LongInt destination. The Velox Val Velox accepts decimal and $/0x hexadecimal forms.
def	LongInt	Value returned whenever Val reports invalid syntax, a partial token or a value outside the 32-bit destination.

Returns

The parsed value in -2147483648..2147483647, or def on conversion failure.

Errors

Ordinary conversion errors return def. Unexpected script stack, string-conversion or allocation failures can still propagate.

Usage notes

This is the safer 32-bit choice when a fallback is acceptable and is the conversion used in existing Velox scripting guidance. Use StrToInt64Def when values can exceed the LongInt range.

Additional Technical Info

StrToIntDef parses a signed 32-bit LongInt and returns the caller's def value for invalid or out-of-range input. It uses the modified PascalScript utility implementation rather than Delphi System.SysUtils.StrToIntDef directly.

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

Implementation

PascalScript installs this as a standard function. Runtime dispatch case 2 passes both arguments to modified uPSUtils.StrToIntDef. That utility converts the script ANSI string to a Delphi string and calls intrinsic System.Val with a LongInt result. It returns def whenever Val reports a non-zero error position.

The public function is therefore behaviourally similar to Delphi SysUtils.StrToIntDef, but its actual terminal and adapter path are PascalScript's modified utility plus System.Val.

Edge cases and quirks

• def is returned for syntax errors and 32-bit range errors alike; the Val error position is discarded.
• A valid input equal to def is indistinguishable from failed conversion.
• Integer parsing is locale-independent and rejects decimal/grouping separators and currency symbols.
• Parsing does not accept a valid prefix and ignore trailing junk; the complete token must convert.
• Delphi documents decimal, $ hexadecimal and 0x hexadecimal forms. Free Pascal Val documents extra binary/octal forms that must not be assumed for Velox.
• The declaration uses LongInt, which is explicitly 32-bit in the reviewed runtime even on a 64-bit host.

Side effects

None.

Performance and concurrency

Linear in input length and independent of locale or mutable shared state.

Related entries

• StrToInt hard-codes -1 as its failure sentinel.
• StrToInt64Def provides the signed 64-bit equivalent.
• StrToUInt64Def parses unsigned 64-bit values.

External references

• Free Pascal System.Val - compatibility reference for the underlying intrinsic model; its additional radix forms are not evidence for Delphi.
• Embarcadero System.Val - the Delphi intrinsic reached by PascalScript's modified utility.

Created 2026-07-15