下表顯示了Objective-C語言支持的所有關係運算符。假設變數A=10，變數B=20，則 -
| 運算符 | 描述 | 示例 |
|---|---|---|
== |
比較兩個運算元的值是否相等; 如果相等，則條件成立。 | (A == B)結果為：false |
!= |
比較兩個運算元的值是否相等; 如果不相等，則條件成立。 | (A != B)結果為：true |
> |
比較左運算元的值是否大於右運算元的值; 如果是，則條件成立。 | (A > B)結果為：false |
< |
比較左運算元的值是否小於右運算元的值; 如果是，則條件成立。 | (A < B)結果為：true |
>= |
比較左運算元的值是否大於等於右運算元的值; 如果是，則條件成立。 | (A >= B)結果為：false |
<= |
比較左運算元的值是否小於等於右運算元的值; 如果是，則條件成立。 | (A <= B)結果為：true |
例子
嘗試以下示例來瞭解Objective-C編程語言中可用的所有關係運算符 -
Live Demo
#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" );
}
}
執行上面示例代碼，得到以下結果：
2018-11-14 05:01:20.415 main[49282] Line 1 - a is not equal to b
2018-11-14 05:01:20.417 main[49282] Line 2 - a is not less than b
2018-11-14 05:01:20.417 main[49282] Line 3 - a is greater than b
2018-11-14 05:01:20.417 main[49282] Line 4 - a is either less than or equal to b
2018-11-14 05:01:20.417 main[49282] Line 5 - b is either greater than or equal to b
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Objective-C運算符
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Objective-C迴圈