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