# Function Reference

# StringIsDigit

Checks if a string contains only digit (0-9) characters.

StringIsDigit ( "string" )

## Parameters

string | The string to check

## Return Value

Success: | 1.
Failure: | 0 if string contains non-digits.

## Remarks

As in other StringIs...() the check is stop if a Chr(0) is encountered inside the string.
Internally the C function is used to speed up the processing.
See examples.

## Related

StringIsAlNum, StringIsAlpha, StringIsASCII, StringIsInt, StringIsLower, StringIsSpace, StringIsUpper, StringIsXDigit

## Example

    #include <MsgBoxConstants.au3>

    MsgBox($MB_SYSTEMMODAL, "", "Is the string 42 a digit: " & StringIsDigit("42") & @CRLF & _ ; Returns 1, as the string contains only digit (0-9) characters.
            "Is the string 00 a digit: " & StringIsDigit("00") & @CRLF & _ ; Returns 1, as the string contains only digit (0-9) characters.
            "Is the string 1.0 a digit: " & StringIsDigit("1.0") & @CRLF & _ ; Returns 0, due to the decimal point.
            "Is the number 1.0 a digit: " & StringIsDigit(1.0) & @CRLF & _ ; Returns 1, due to the number to string conversion.
            "Is the string 1+2 a digit: " & StringIsDigit("1+2") & @CRLF) ; Returns 0, as the + (plus) symbol is present in the string.