The ASC() function takes the first char of a string and returns its numeric PETSCII code. If an empty string is provided, the function will return 0.

The inverse function of ASC() is CHR$.

DECLARE FUNCTION ASC AS BYTE (char$ AS STRING) SHARED STATIC INLINE

PRINT ASC("a") : REM will print 65
PRINT ASC("abc") : REM will print 65
PRINT ASC("") : REM will print 0