Objective-C 中的赋值运算符
Objective-C 语言支持的赋值运算符如下 −
| 运算符 | 描述 | 示例 |
|---|---|---|
| = | 简单赋值运算符，将右侧操作数的值分配给左侧操作数 | C = A + B 会将 A + B 的值赋给 C |
| += | 添加AND赋值运算符，将右操作数与左操作数相加，并将结果赋值给左操作数 | C += A 等价于 C = C + A |
| -= | 减与赋值运算符，左操作数减去右操作数，结果赋给左操作数 | C -= A 等同于 C = C - A |
| *= | 乘与赋值运算符，将右操作数与左操作数相乘，并将结果赋给左操作数 | C *= A 等同于 C = C * A |
| /= | 除与赋值运算符，将左操作数与右操作数相除，并将结果赋给左操作数 | C /= A 等同于 C = C / A |
| %= | 模数与赋值运算符，它使用两个操作数取模并将结果分配给左操作数 | C %= A 等同于 C = C % A |
| <<= | 左移与赋值运算符 | C <<= 2 等同于 C = C << 2 |
| >>= | 右移与赋值运算符 | C >>= 2 等同于 C = C >> 2 |
| &= | 按位与赋值运算符 | C &= 2 等同于 C = C & 2 |
| ^= | 按位异或和赋值运算符 | C ^= 2 等同于 C = C ^ 2 |
| |= | 按位包含或和赋值运算符 | C |= 2 等同于 C = C | 2个 |
示例
尝试以下示例来理解 Objective-C 编程语言中可用的所有赋值运算符 −
#import <Foundation/Foundation.h>
int main() {
int a = 21;
int c ;
c = a;
NSLog(@"Line 1 - = Operator Example, Value of c = %d\n", c );
c += a;
NSLog(@"Line 2 - += Operator Example, Value of c = %d\n", c );
c -= a;
NSLog(@"Line 3 - -= Operator Example, Value of c = %d\n", c );
c *= a;
NSLog(@"Line 4 - *= Operator Example, Value of c = %d\n", c );
c /= a;
NSLog(@"Line 5 - /= Operator Example, Value of c = %d\n", c );
c = 200;
c %= a;
NSLog(@"Line 6 - %= Operator Example, Value of c = %d\n", c );
c <<= 2;
NSLog(@"Line 7 - <<= Operator Example, Value of c = %d\n", c );
c >>= 2;
NSLog(@"Line 8 - >>= Operator Example, Value of c = %d\n", c );
c &= 2;
NSLog(@"Line 9 - &= Operator Example, Value of c = %d\n", c );
c ^= 2;
NSLog(@"Line 10 - ^= Operator Example, Value of c = %d\n", c );
c |= 2;
NSLog(@"Line 11 - |= Operator Example, Value of c = %d\n", c );
}
当你编译并执行上面的程序时，它会产生以下结果 −
2013-09-07 22:00:19.263 demo[21858] Line 1 - = Operator Example, Value of c = 21 2013-09-07 22:00:19.263 demo[21858] Line 2 - += Operator Example, Value of c = 42 2013-09-07 22:00:19.263 demo[21858] Line 3 - -= Operator Example, Value of c = 21 2013-09-07 22:00:19.263 demo[21858] Line 4 - *= Operator Example, Value of c = 441 2013-09-07 22:00:19.263 demo[21858] Line 5 - /= Operator Example, Value of c = 21 2013-09-07 22:00:19.264 demo[21858] Line 6 - %= Operator Example, Value of c = 11 2013-09-07 22:00:19.264 demo[21858] Line 7 - <<= Operator Example, Value of c = 44 2013-09-07 22:00:19.264 demo[21858] Line 8 - >>= Operator Example, Value of c = 11 2013-09-07 22:00:19.264 demo[21858] Line 9 - &= Operator Example, Value of c = 2 2013-09-07 22:00:19.264 demo[21858] Line 10 - ^= Operator Example, Value of c = 0 2013-09-07 22:00:19.264 demo[21858] Line 11 - |= Operator Example, Value of c = 2
objective_c_operators.html
