Shl

From Lazarus wiki
Revision as of 14:49, 24 March 2012 by Vincent (talk | contribs) (Text replace - "delphi>" to "syntaxhighlight>")
Jump to navigationJump to search

Shift left (shl) performs a left bit-shift operation (opposite than shr).

E.g 

Command is:  00000100  shl 2
 
Action is:  00000100 <- 00
 
Result is:  00010000

Clear a bit

function ClearBit( const aValue, aBitNumber : integer ) : integer;
begin
   result := aValue and not( 1 shl aBitNumber );
end;

If you call ClearBit(%1111,1) then get %1101 (%1111 = 15 and %1101 = 13). If you call ClearBit(13,2) then get 9 (9 = %1001) .

See e.g

Retrieved from "http://wiki.freepascal.org/index.php?title=Shl&oldid=56354"