Objective-C语法应用

简单的动物园系统实现

#import <Foundation/Foundation.h>
#import "Animal.h"

//动物园
@interface Zoo : NSObject

@property (nonatomic, strong) Animal *animal;//动物
@property (nonatomic, assign) int foodSave;//食物储备

/**
 *  初始化方法 传入储备的食物数量
 */
- (id)initWithFoodSave:(int)foodSave;

@end

#import "Zoo.h"

@implementation Zoo

- (id)initWithFoodSave:(int)foodSave {
    if (self = [super init]) {
        _foodSave = foodSave;
    }
    return self;
}

@end

动物园中有各种动物,以下代码构建动物类,以继承方式实现:

#import <Foundation/Foundation.h>

@interface Animal : NSObject

@property (nonatomic, assign) int count;//数量
@property (nonatomic, assign) int eatFood;//食量
@property (nonatomic, assign) int productionCycle;//生产周期

//自定义初始化 传入3个参数:1.当前动物数量 2.当前动物每天吃的食物数量 3.生产周期为多少天
- (id)initWithCount:(int)cout andEatFood:(int)eatFood andProductionCycle:(int)productionCycle;

//吃东西
- (int)animalEatFood;

//生宝宝
- (int)productionBaby;

@end

#import "Animal.h"

@implementation Animal

- (id)initWithCount:(int)cout andEatFood:(int)eatFood andProductionCycle:(int)productionCycle {
    if (self = [super init]) {
        self.count = cout;
        self.eatFood = eatFood;
        self.productionCycle = productionCycle;
    }
    return self;
}

//吃东西
- (int)animalEatFood {
    NSLog(@"吃东西了!!!! %d %d", self.eatFood, self.count);
    return self.eatFood * self.count;
}

//生宝宝
- (int)productionBaby {
    return 0;
}

@end

#import "Animal.h"

@interface Panda : Animal

@end

#import "Panda.h"

@implementation Panda

//重写父类方法
- (int)animalEatFood {
    NSLog(@"熊猫吃掉 %d 个单位的食物, 现有 %d 只", self.eatFood * self.count, self.count);
    return self.eatFood * self.count;
}

- (int)productionBaby {
    NSLog(@"熊猫生产了 3 个宝宝");
    self.count += 3;
    return 3;
}

@end

#import "Animal.h"

@interface Elephant : Animal

@end

#import "Elephant.h"

@implementation Elephant

- (int)animalEatFood {
    NSLog(@"大象吃掉 %d 个单位的食物, 现有 %d 只", self.eatFood * self.count, self.count);
    return self.eatFood * self.count;
}

- (int)productionBaby {
    NSLog(@"大象生产了 1 个宝宝");
    self.count += 1;
    return 1;
}

@end

#import "Animal.h"

@interface Kangaroo : Animal

@end

#import "Kangaroo.h"

@implementation Kangaroo

- (int)animalEatFood {
    NSLog(@"袋鼠吃掉 %d 个单位的食物, 现有 %d 只", self.eatFood * self.count, self.count);
    return self.eatFood * self.count;
}

- (int)productionBaby {
    NSLog(@"袋鼠生产了 2 个宝宝");
    self.count += 2;
    return 2;
}

@end

以下是main函数中的测试代码:

#import <Foundation/Foundation.h>
#import "Zoo.h"
#import "Panda.h"
#import "Elephant.h"
#import "Kangaroo.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //创建动物员对象 并对储存的食物进行初始化
        Zoo *zoo = [[Zoo alloc] initWithFoodSave:1000];
        //初始化各种动物信息 (运用多态)
        Animal *panda = [[Panda alloc] initWithCount:2 andEatFood:1 andProductionCycle:3];
        Animal *elephant = [[Elephant alloc] initWithCount:2 andEatFood:5 andProductionCycle:5];
        Animal *kangaroo = [[Kangaroo alloc] initWithCount:2 andEatFood:2 andProductionCycle:4];

        int day = 1;
        while (zoo.foodSave > 0) {
            //到了动物的生产周期时,动物开始生产
            if (day % panda.productionCycle == 0) {
                [panda productionBaby];
            }
            if (day % elephant.productionCycle == 0) {
                [elephant productionBaby];
            }
            if (day % kangaroo.productionCycle == 0) {
                [kangaroo productionBaby];
            }

            int usedFood = [panda animalEatFood] + [elephant animalEatFood] + [kangaroo animalEatFood];
            zoo.foodSave -= usedFood;

            NSLog(@"第%d天,剩余食物%d", day++, zoo.foodSave);
            //如果食物已经不足动物使用一天,那就必须要采购了,此时应该不再继续,因此让食物为0
            if (zoo.foodSave < usedFood) {
                zoo.foodSave = 0;
            }
        }
    }
    return 0;
}