day02-03-3练习:狗比较速度

Objective-c

//  main.m
//  狗比较速度
//
//  Created by Aaron on 15/7/2.
//  Copyright (c) 2015年 Aaron. All rights reserved.
//
#import <Foundation/Foundation.h>
#import "Dog.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Dog *d1 = [[Dog alloc] initWithSpeed:5];
        Dog *d2 = [[Dog alloc] initWithSpeed:10];
        NSLog(@"%ld",[d2 compareWithOtherDog:d1]);
    }
    return 0;
}

import <Foundation/Foundation.h>
/*
 设计一个狗类Dog,给类添加一个方法,该方法用来比较狗A与另外一只狗B的速度,如果A的速度快,返回1,如果B的速度快,返回-1,相同则返回0.
 */
@interface Dog : NSObject
{
    NSInteger _speed;
}
-(instancetype)initWithSpeed:(NSInteger)speed;
-(NSInteger)compareWithOtherDog:(Dog *)dog;
@end

#import "Dog.h"
@implementation Dog
-(instancetype)initWithSpeed:(NSInteger)speed
{
    if(self = [super init])
    {
        _speed = speed;
    }
    return self;
}
-(NSInteger)compareWithOtherDog:(Dog *)dog
{
    if(_speed > [dog speed])
    {
        return 1;
    }
    else if(_speed == [dog speed])
    {
        return 0;
    }
    else
    {
        return -1;
    }
}
-(NSInteger)speed
{
    return _speed;
}
@end