Day4

#import "Person.h"

@implementation Person

- (void)dealloc
{
    NSLog(@"person destroy");
}

@end

//
//  ViewController.m
//  BasicKnowledge
//
//  Created by xin on 15-3-16.
//  Copyright (c) 2015年 Jackey. All rights reserved.
//

#import "ViewController.h"
#import "Person.h"
@interface ViewController ()
@property (nonatomic,strong) Person *person;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
    //strong pointer
    //won‘t release the memory
    //默认的是强指针
    //不执行销毁语句
    self.person = [[Person alloc]init];
    
    //这里是强指针，但是这是个局部对象，在viewdidload执行完后会执行销毁语句
    Person *person1 = [[Person alloc]init];
    
    //立即释放
    __weak Person *person2 = [[Person alloc]init];
    //strong weak 的区别：
    //strong为持有者，weak为观望者，就像strong是一条狗链子
    NSLog(@"-----");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

//
//  ViewController.m
//  BasicKnowledge
//
//  Created by xin on 15-3-16.
//  Copyright (c) 2015年 Jackey. All rights reserved.
//

#import "ViewController.h"
#import "Person.h"
@interface ViewController ()
@property (nonatomic,strong) Person *person;
@property (nonatomic,weak) Person *weakPerson;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
    //strong pointer
    //won‘t release the memory
    //默认的是强指针
    //不执行销毁语句
    //体现strong和weak的区别
    //strong 为持有者，牵着person对象，weakperson为虚指向person对象
    //下面的情况，weakperson不会被自动销毁
    self.person = [[Person alloc]init];
    self.weakPerson = self.person;
    
    NSLog(@"-----");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

    //拖拉的控件用weak
    //属性对象用strong
    //整数非对象类型用assign
　　//NSString 用copy