Difference between revisions of "Shl"

From Free Pascal wiki
Jump to navigationJump to search
m
m
Line 6: Line 6:
  
 
E.g
 
E.g
  Command is: 00000100 shl 2
+
  Command is: 00000100 shl 2
 
    
 
    
 
  Action is:  00000100 <- 00 (00 gets added to the right of the value; left 00 "disappears")
 
  Action is:  00000100 <- 00 (00 gets added to the right of the value; left 00 "disappears")

Revision as of 10:32, 15 October 2014

Template:shl

Overview

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

E.g

Command is: 00000100 shl 2
 
Action is:  00000100 <- 00 (00 gets added to the right of the value; left 00 "disappears")
 
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 you get %1101 (%1111 = 15 and %1101 = 13).

If you call ClearBit(13,2), then you get 9 (9 = %1001) .

See also