Objective-C中的关系运算符

下表显示了Objective-C语言支持的所有关系运算符。假设变量A为10，变量B为20，则：

示例

尝试以下示例以了解Objective-C编程语言中可用的所有关系运算符：

#import <Foundation/Foundation.h>

int main() {
   int a = 21;
   int b = 10;

   if( a == b ) {
      NSLog(@"Line 1 - a is equal to b\n" );
   } else {
      NSLog(@"Line 1 - a is not equal to b\n" );
   }
   
   if ( a < b ) {
      NSLog(@"Line 2 - a is less than b\n" );
   } else {
      NSLog(@"Line 2 - a is not less than b\n" );
   } 
   
   if ( a > b ) {
      NSLog(@"Line 3 - a is greater than b\n" );
   } else {
      NSLog(@"Line 3 - a is not greater than b\n" );
   }
   
   /* Lets change value of a and b */
   a = 5;
   b = 20;
   
   if ( a <= b ) {
      NSLog(@"Line 4 - a is either less than or equal to  b\n" );
   }
   
   if ( b >= a ) {
      NSLog(@"Line 5 - b is either greater than  or equal to b\n" );
   }
}

编译并执行上述程序后，会产生以下结果：

2013-09-07 22:42:18.254 demo[9486] Line 1 - a is not equal to b
2013-09-07 22:42:18.254 demo[9486] Line 2 - a is not less than b
2013-09-07 22:42:18.254 demo[9486] Line 3 - a is greater than b
2013-09-07 22:42:18.254 demo[9486] Line 4 - a is either less than or equal to  b
2013-09-07 22:42:18.254 demo[9486] Line 5 - b is either greater than  or equal to b