Objective-Cのビット演算子

Objective-C言語でサポートされているビット単位の演算子を次の表にリストします。変数Aが60を保持し、変数Bが13を保持すると仮定します-

Operator	Description	Example
&	Binary AND Operator copies a bit to the result if it exists in both operands.	(A & B) will give 12, which is 0000 1100
		Binary OR Operator copies a bit if it exists in either operand.
(A	B) will give 61, which is 0011 1101	^
Binary XOR Operator copies the bit if it is set in one operand but not both.	(A ^ B) will give 49, which is 0011 0001	~
Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.	(~A ) will give -61, which is 1100 0011 in 2’s complement form.	<<
Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.	A << 2 will give 240, which is 1111 0000	>>

例

次の例を試して、Objective-Cプログラミング言語で使用できるすべてのビット演算子を理解してください-

#import <Foundation/Foundation.h>

int main() {
   unsigned int a = 60;   /*60 = 0011 1100*/
   unsigned int b = 13;   /*13 = 0000 1101*/
   int c = 0;

   c = a & b;         /*12 = 0000 1100*/
   NSLog(@"Line 1 - Value of c is %d\n", c );

   c = a | b;          /*61 = 0011 1101*/
   NSLog(@"Line 2 - Value of c is %d\n", c );

   c = a ^ b;          /*49 = 0011 0001*/
   NSLog(@"Line 3 - Value of c is %d\n", c );

   c = ~a;             /*-61 = 1100 0011 */
   NSLog(@"Line 4 - Value of c is %d\n", c );

   c = a << 2;         /*240 = 1111 0000*/
   NSLog(@"Line 5 - Value of c is %d\n", c );

   c = a >> 2;         /*15 = 0000 1111*/
   NSLog(@"Line 6 - Value of c is %d\n", c );
}

上記のプログラムをコンパイルして実行すると、次の結果が生成されます-

2013-09-07 22:11:51.652 demo[30836] Line 1 - Value of c is 12
2013-09-07 22:11:51.652 demo[30836] Line 2 - Value of c is 61
2013-09-07 22:11:51.652 demo[30836] Line 3 - Value of c is 49
2013-09-07 22:11:51.652 demo[30836] Line 4 - Value of c is -61
2013-09-07 22:11:51.652 demo[30836] Line 5 - Value of c is 240
2013-09-07 22:11:51.652 demo[30836] Line 6 - Value of c is 15

Objective-c-bitwise-operators

Objective-Cのビット演算子

例