Objective-Cの関係演算子

次の表は、Objective-C言語でサポートされているすべての関係演算子を示しています。変数 A が10を保持し、変数 B が20を保持すると仮定します-

Operator	Description	Example
==	Checks if the values of two operands are equal or not; if yes, then condition becomes true.	(A == B) is not true.
!=	Checks if the values of two operands are equal or not; if values are not equal, then condition becomes true.	(A != B) is true.
>	Checks if the value of left operand is greater than the value of right operand; if yes, then condition becomes true.	(A > B) is not true.
<	Checks if the value of left operand is less than the value of right operand; if yes, then condition becomes true.	(A < B) is true.
>=	Checks if the value of left operand is greater than or equal to the value of right operand; if yes, then condition becomes true.	(A >= B) is not true.
⇐	Checks if the value of left operand is less than or equal to the value of right operand; if yes, then condition becomes true.	(A ⇐ B) is true.

例

次の例を試して、Objective-Cプログラミング言語で使用可能なすべての関係演算子を理解してください-

#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" );
   }
}

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 22:42:18.254 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

Objective-c-relational-operators

Objective-Cの関係演算子

例