下表显示了Objective-C语言支持的所有关系运算符。假设变量A=10
,变量B=20
,则 -
运算符 | 描述 | 示例 |
---|---|---|
== |
比较两个操作数的值是否相等; 如果相等,则条件成立。 | (A == B) 结果为:false |
!= |
比较两个操作数的值是否相等; 如果不相等,则条件成立。 | (A != B) 结果为:true |
> |
比较左操作数的值是否大于右操作数的值; 如果是,则条件成立。 | (A > B) 结果为:false |
< |
比较左操作数的值是否小于右操作数的值; 如果是,则条件成立。 | (A < B) 结果为:true |
>= |
比较左操作数的值是否大于等于右操作数的值; 如果是,则条件成立。 | (A >= B) 结果为:false |
<= |
比较左操作数的值是否小于等于右操作数的值; 如果是,则条件成立。 | (A <= B) 结果为:true |
例子
尝试以下示例来了解Objective-C编程语言中可用的所有关系运算符 -
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" );
}
}
执行上面示例代码,得到以下结果:
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