OC中類方法的使用實例

#import <Foundation/Foundation.h>

//車輛類的聲明
@interface Car : NSObject
{
    int _speed;
}

-(void)setSpeed:(int)speed;
-(int)getSpeed;
/**
    比較兩輛車字速度的類方法，如果aCar的速度比bCar快，
    那麼返回YES，否則返回NO
 */
+(BOOL)isFaster:(Car*)aCar thanThe:(Car*)bCar;

@end

//車輛類的實現
@implementation Car

-(void)setSpeed:(int)speed{
    self->_speed = speed;
}
-(int)getSpeed{
    return _speed;
}
+(BOOL)isFaster:(Car*)aCar thanThe:(Car*)bCar{
    if ([aCar getSpeed]>[bCar getSpeed]) {
        return YES;
    }else{
        return NO;
    }
}
@end


int main(){
    Car *aCar = [Car new];
    Car *bCar = [Car new];
    [aCar setSpeed:90];
    [bCar setSpeed:100];
    //調用類方法來比較aCar和bCar的速度
    if ([Car isFaster:aCar thanThe:bCar]) {
        NSLog(@"A車比B車快");
    }else{
        NSLog(@"A車比B車慢");
    }
    
    return 0;
}

還是直接上代碼比較實在