Table of Contents
SHL
The SHL()
function returns a number bit-shifted <n> positions to the left.
Function header
DECLARE FUNCTION SHL AS BYTE (num AS BYTE, n AS BYTE) SHARED STATIC INLINE DECLARE FUNCTION SHL AS INT (num AS INT, n AS BYTE) OVERLOAD SHARED STATIC INLINE DECLARE FUNCTION SHL AS WORD (num AS WORD, n AS BYTE) OVERLOAD SHARED STATIC INLINE DECLARE FUNCTION SHL AS LONG (num AS LONG, n AS BYTE) OVERLOAD SHARED STATIC INLINE
Each bit in the number will be moved <n> positions to the left. The least significant bit will be filled with zero, whereas the most significant bit will be discarded.
Note
Since SHL(number, n)
equals number * pow(2, n)
, the function is especially useful if you want to multiply a number by powers of two. Bit shifting is carried out much faster than the multiplication operation.
Example
PRINT SHL(41, 1) : REM outputs 82 PRINT SHL(%00001111, 4) : REM outputs 240 (binary 11110000) PRINT SHL(%10000000, 1) : REM outputs 0 because the MSB is discarded PRINT SHL(CWORD(%10000000), 0) : REM outputs 256 because this time REM the argument is 16 bits wide