发布于 2015-07-05 11:49:42 | 181 次阅读 | 评论: 0 | 来源: 网络整理
下表中列出了支持Objective-C语言的位运算符。假设变量A=60和变量B=13，则：
| 运算符 | 描述说明 | 示例 |
|---|---|---|
| & | 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 due to a signed binary number. |
| << | Binary Left Shift Operator. The left operand's value is moved left by the number of bits specified by the right operand. | A << 2 will give 240, which is 1111 0000 |
| >> | Binary Right Shift Operator. The left operand's value is moved right by the number of bits specified by the right operand. | A >> 2 will give 15, which is 0000 1111 |
尝试下面的例子就明白了所有在Objective-C编程语言的位运算符：
#import <Foundation/Foundation.h>
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 %dn", c );
c = a | b; /* 61 = 0011 1101 */
NSLog(@"Line 2 - Value of c is %dn", c );
c = a ^ b; /* 49 = 0011 0001 */
NSLog(@"Line 3 - Value of c is %dn", c );
c = ~a; /*-61 = 1100 0011 */
NSLog(@"Line 4 - Value of c is %dn", c );
c = a << 2; /* 240 = 1111 0000 */
NSLog(@"Line 5 - Value of c is %dn", c );
c = a >> 2; /* 15 = 0000 1111 */
NSLog(@"Line 6 - Value of c is %dn", c );
}
当编译和执行上述程序，它会产生以下结果：
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