//set方法/get方法的声明和实现;

@import<Foundation/Foundation.h>

@interface Car: NSObject

{

    int _wheels;

}

//set方法get方法的声明

- (void)setWheels(int) wheels;

- (int)wheels;

@end

@implementation

//set方法get方法的实现

- (void)setWheels(int) wheels

{

    if(wheels<=0){      //封装的好处:过滤不合理的值

        wheels=1;

    }

    _wheels=wheels;

}

- (int)wheels

{

    return _wheels;

}

@end

int main(){

    Car *car1 = [Car new];

    int aNum=7;

    [car1 aNum];

    [car1 wheels];              //读取wheels的值而不是_wheels

   

   

    return 0;

}

这么长!

good！！！

good！！！

写的不错喔