Objective-C sizeof 和三元运算符

Objective-C 支持的其他少量重要运算符，包括 sizeof 和 ? ::

实例

尝试以下实例以了解 Objective-C 编程语言中可用的所有其他运算符:

#import <Foundation/Foundation.h>
int main() {
  int a = 4;
  short b;
  double c;
  int* ptr;
  /* example of sizeof operator */
  NSLog(@"Line 1 - Size of variable a = %d\n", sizeof(a) );
  NSLog(@"Line 2 - Size of variable b = %d\n", sizeof(b) );
  NSLog(@"Line 3 - Size of variable c= %d\n", sizeof(c) );
  /* example of &amp; and * operators */
  ptr = &a;/* 'ptr' now contains the address of 'a'*/
  NSLog(@"value of a is %d\n", a);
  NSLog(@"*ptr is %d.\n", *ptr);
  /* example of ternary operator */
  a = 10;
  b = (a == 1) ? 20: 30;
  NSLog(@"Value of b is %d\n", b );
  b = (a == 10) ? 20: 30;
  NSLog(@"Value of b is %d\n", b );
}

结果如下:

2022-07-07 22:46:22.702 demo[24593] Line 1 - Size of variable a = 4
2022-07-07 22:46:22.703 demo[24593] Line 2 - Size of variable b = 2
2022-07-07 22:46:22.703 demo[24593] Line 3 - Size of variable c= 8
2022-07-07 22:46:22.703 demo[24593] value of a is 4
2022-07-07 22:46:22.703 demo[24593] *ptr is 4.
2022-07-07 22:46:22.703 demo[24593] Value of b is 30
2022-07-07 22:46:22.703 demo[24593] Value of b is 20