深复制 浅复制

深复制：不仅复制对象 还复制对象关联的对象

浅复制：只是复制对象本身 不复制对象关联的对象

//
//  main.m
//  对象的复制
//
//  Created by MAC on 15/12/20.
//  Copyright © 2015年 MAC. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //深复制  把对象关联的对象也复制
        NSMutableString *m1 = [NSMutableString stringWithString:@"one"];
         NSMutableString *m2 = [NSMutableString stringWithString:@"two"];
         NSMutableString *m3 = [NSMutableString stringWithString:@"three"];

        NSMutableArray *arr = [NSMutableArray arrayWithCapacity:10];
        [arr addObject:m1];
        [arr addObject:m2];
        [arr addObject:m3];
        NSMutableArray *arr1 = [arr mutableCopy];//只是赋值对象本身 关联的对象不复制  浅复制
        NSLog(@"%@",arr);
         NSLog(@"%@",arr1);

       // [arr removeObject:@"one"]; //删除字符串不会影响

        [arr1 removeAllObjects];
        for (NSObject *s in arr) {      //深复制
            NSObject *temp = [s mutableCopy]; //把里面的对象拿出来复制给另一个数组
            [arr1 addObject:temp];
        }

        [m1 insertString:@"changed" atIndex:1]; //浅复制情况下改变数组的关联对象也会受影响 但深复制不受影响
        NSLog(@"%@",arr);
        NSLog(@"%@",arr1);
//        //浅复制
//        // copy
//        //mutableCopy 可变的
        NSMutableString *str = [NSMutableString stringWithString:@"Hello World"];
        NSMutableString *str2 = str;
        NSLog(@"%p",str);
        NSLog(@"%p",str2);
        [str insertString:@"Changed" atIndex:3];
        //修改第一个第二个String也被修改 因为内存地址一样
        NSLog(@"%@",str);
        NSLog(@"%@",str2);
//
        NSMutableArray *array = [NSMutableArray arrayWithCapacity:10];
        [array addObject:@"1"];
        [array addObject:@"2"];
        [array addObject:@"3"];
        NSMutableArray *array2 = array;  //内存地址一样
        NSLog(@"%p",array);
        NSLog(@"%p",array2);
        [array removeObject:@"2"];

       array2 = [array mutableCopy]; //copy内存地址不一样
        NSLog(@"%p",array);
        NSLog(@"%p",array2);
//
//
        //自定义对象复制
        Person *per = [[Person alloc]init];
        per->age = 20;
        Person *p2 = per;       //内存地址一样 NSString
       Person *p3 = [per copy];   //-[Person copyWithZone:]: unrecognized selector sent to instance 没有找到此方法 需要实现NSCopying协议里面的- (id)copyWithZone:(nullable NSZone *)zone;方法
        NSLog(@"=%p",per);
        NSLog(@"=%p",p3);
        NSLog(@"%d",p2->age);
        per->age = 10;
        NSLog(@"%d",p2->age);

        NSMutableSet *mset = [NSMutableSet setWithCapacity:10];
        [mset addObject:@"one"];
        [mset addObject:@"two"];
        [mset addObject:@"three"];
        [mset addObject:@"four"];
        NSMutableSet *mset2 = [mset mutableCopy]; //使用mutableCopy 内存地址不一样
        NSLog(@"%p",mset);
        NSLog(@"%p",mset2);

    }
    return 0;
}

//
//  Person.h
//  对象的复制
//
//  Created by MAC on 15/12/20.
//  Copyright © 2015年 MAC. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCopying>
{
    @public
    int age;

}
@property(nonatomic)int age;
@property(nonatomic,copy)NSString *name;
@property(nonatomic)int num;
@end
//
//  Person.m
//  对象的复制
//
//  Created by MAC on 15/12/20.
//  Copyright © 2015年 MAC. All rights reserved.
//

#import "Person.h"

@implementation Person
- (id)copyWithZone:(nullable NSZone *)zone{
    Person *per = [[Person allocWithZone:zone]init];
    NSLog(@"copy per");
    return per;
}
@end