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HexToInt

function HexToInt(HexNum: String): Int64;

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := HexToInt('2A');  // 42
end;

Usage​

HexToInt parses hexadecimal text as an Int64 after Velox prepends Velox's dollar-sign base prefix.

Parameters

NameTypeDescription
HexNumStringOne to sixteen hexadecimal digits with no prefix, sign, whitespace or separator. Both letter cases are accepted.

Returns

The signed 64-bit interpretation of the hexadecimal bit pattern. Values through 7FFFFFFFFFFFFFFF are positive. A full 16-digit pattern with its high bit set is interpreted as two's complement; for example, FFFFFFFFFFFFFFFF returns -1 and 8000000000000000 returns the minimum Int64.

Errors

Velox raises EConvertError when the prefixed text is not a valid 64-bit integer representation. Allocation failures can also propagate. No default value or partial parse is returned.

Usage notes

Validate an explicit 1..16 hexadecimal-digit contract at an external boundary. If the destination expects an unsigned magnitude, handle values above 7FFFFFFFFFFFFFFF with an appropriate unsigned representation rather than interpreting this signed result as positive.

Additional Technical Info​

HexToInt strictly parses hexadecimal digits into a signed 64-bit Int64. Velox prepends Delphi's $ base marker and passes the resulting string to System.SysUtils.StrToInt64.

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

Implementation

The Velox wrapper evaluates StrToInt64('$' + HexNum). The selected Delphi parser recognises $ as hexadecimal and accumulates up to 64 bits before returning an Int64. No locale-dependent punctuation is involved.

Edge cases and quirks

  • The caller must omit the prefix. Passing $2A produces $$2A; passing 0x2A produces $0x2A. Both are invalid.
  • A leading plus or minus sign is invalid because Velox places $ before the original text.
  • Empty input, whitespace and embedded/trailing separators are invalid.
  • Up to 16 hexadecimal digits can represent a complete 64-bit bit pattern. A 17th digit or another out-of-range form raises rather than truncating.
  • This is a signed-bit-pattern conversion, not an unsigned 64-bit return. Values with bit 63 set appear negative.

Side effects

None outside temporary/result string allocation.

Performance and concurrency

Linear in the short input length with no shared mutable state or locale dependency.

Related entries

  • IntToHex provides the signed Int64 hexadecimal formatter.
  • HexToBin decodes pairs into a stream but has a different, permissive failure contract.
  • BinToInt performs Velox's permissive 32-bit positional binary scan.

External references

Created 2026-07-15