iOS OC10_Block

内存五大区域

    //栈    int a=10;    NSLog(@"%p",a);    //堆    int *p=malloc(40);    NSLog(@"%p",p);    //全局    static int b=10;    NSLog(@"%p",b);    //常量    char *str="iphone";    NSLog(@"%p",str);    //代码区   NSLog(@"%p",maxValue);

结果

2015-07-28 19:07:07.976 OC10_Block[829:71750] 0xa2015-07-28 19:07:07.977 OC10_Block[829:71750] 0x1001068d02015-07-28 19:07:07.977 OC10_Block[829:71750] 0xa2015-07-28 19:07:07.977 OC10_Block[829:71750] 0x100001f75

Block的四种形式

//1.无参数,无返回值 void(^block)()=^(){ //函数大括号里的代码段 NSLog(@"今天有点多云"); }; //block的使用 block(); //block自己不会执行,必须调用才会执行block大括号里的代码段

结果

2015-07-28 19:25:43.452 OC10_Block[1239:82416] 今天有点多云

//2.有参数无返回值void (^block)(int ,int)=^(int a,int b){int max=a > b ? a : b;NSLog(@"%d",max);    };//调用block(10,20);//void (^block)(int ,int)是block的类型,它的名是block,我们也通过名进行调用

结果

2015-07-28 19:27:08.121 OC10_Block[1249:82981] 20

//3.有返回值无参数//有返回值在函数段的最后要加上returnint(^block)()=^(){return 100;};//block调用时没有参数也要加上括号NSLog(@"%d",block());

结果

2015-07-28 19:28:07.938 OC10_Block[1256:83327] 100

    //4.有参数有返回值    NSString *(^block)(NSArray *,NSInteger)=^(NSArray *arr,NSInteger index){        return arr[index];    };    NSLog(@"%@",block(@[@"1",@"2"],1));

结果

2015-07-28 19:29:05.096 OC10_Block[1263:84049] 2

练习

    //返回整数,参数字符串    NSInteger (^block)(NSString *)=^(NSString *str){        return str.integerValue;    };    NSLog(@"%ld",block(@"111"));

结果

2015-07-28 19:30:42.921 OC10_Block[1271:85319] 111

    //参数日期字符串,返回NSDate类型的日期对象    NSDate *(^block)(NSString *)=^(NSString *str){        NSDateFormatter *formatter=[[NSDateFormatter alloc] init];        [formatter setDateFormat:@"yyyy-MM-dd HH-mm-ss"];        return [formatter dateFromString:str];    };    NSLog(@"%@",block(@"2015-07-28 10:12:12"));    //block的函数段中更多使用参数,而返回值更多是调用一方使用

结果

2015-07-28 19:31:33.543 OC10_Block[1278:86117] 2015-07-28 02:12:12 +0000

//通过新的block写一个block    Block block=^(NSArray *arr){        return arr[0];    };

    //block和局部变量    //__block相当于给a一个在block中修改的权限,否则他只能取值,不能赋值    __block int a=10;    void(^block)()=^(){        a=10*a;        NSLog(@"%d",a);    };    block();

结果

2015-07-28 19:33:14.295 OC10_Block[1301:87551] 100

    //通过block对数组进行遍历    NSArray *arr=[NSArray arrayWithObjects:@"1",@"2",@"3",@"4",@"5",@"6", nil];    //系统的block    [arr enumerateObjectsUsingBlock:^(NSString * obj, NSUInteger idx, BOOL *stop) {        NSLog(@"%@",obj);    }];    //系统的block的用法就是回车

结果

2015-07-28 19:33:52.913 OC10_Block[1308:88218] 12015-07-28 19:33:52.914 OC10_Block[1308:88218] 22015-07-28 19:33:52.914 OC10_Block[1308:88218] 32015-07-28 19:33:52.914 OC10_Block[1308:88218] 42015-07-28 19:33:52.915 OC10_Block[1308:88218] 52015-07-28 19:33:52.915 OC10_Block[1308:88218] 6

    //数组排序    //数组对字符串的排序    //不可变的数组NSArray*arr=@[@"zhangyangyang",@"wuhe",@"liushansahn",@"wangjunmin",@"yanglin"]; //SEL是方法选择器,他是方法选择器的类型NSArray*newArr[arrsortedArrayUsingSelector:@selector(compare:)];NSLog(@"%@",newArr);NSLog(@"%@",arr);

结果

2015-07-28 19:35:02.000 OC10_Block[1319:89130] (    zhangyangyang,    wuhe,    liushansahn,    wangjunmin,    yanglin)

    //可变数组NSMutableArray*arr[NSMutableArrayarrayWithObjects:@"zhangyangyang",@"wuhe",@"liushansahn",@"wangjunmin",@"yanglin", nil];[arr sortUsingSelector:@selector(compare:)];NSLog(@"%@",arr);

结果

2015-07-28 19:36:27.541 OC10_Block[1326:90109] (    liushansahn,    wangjunmin,    wuhe,    yanglin,    zhangyangyang)

    //数组对对象的排序    //新建四个人    Person *per1=[Person baseWithName:@"yanglin" sex:@"nan"];    Person *per2=[Person baseWithName:@"wuhe" sex:@"nan"];    Person *per3=[Person baseWithName:@"cunmou" sex:@"nv"];    Person *per4=[Person baseWithName:@"liushanshan" sex:@"nan"];    //用字面量创建对象和便利构造器是一样的    NSArray *arr=@[per1,per2,per3,per4];    //以学生的姓名作为排序的依据NSArray*newArr[arrsortedArrayUsingComparator:^NSComparisonResult(Person * obj1, Person* obj2) {      return -[obj1.name compare:obj2.name];  }];    for (Person *per in newArr) {       NSLog(@"%@",per.name);    }

结果

2015-07-28 19:37:53.065 OC10_Block[1340:91155] yanglin2015-07-28 19:37:53.066 OC10_Block[1340:91155] wuhe2015-07-28 19:37:53.066 OC10_Block[1340:91155] liushanshan2015-07-28 19:37:53.066 OC10_Block[1340:91155] cunmou

    Person *per1=[Person baseWithName:@"yanglin" sex:@"nan"];    Person *per2=[Person baseWithName:@"wuhe" sex:@"nan"];    Person *per3=[Person baseWithName:@"cunmou" sex:@"nv"];    Person *per4=[Person baseWithName:@"liushanshan" sex:@"nan"];        NSMutableArray *marr=[NSMutableArray arrayWithObjects:per1,per2,per3,per4, nil];    [marr sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {        Person *per11=(Person *)obj1;        Person *per22=(Person *)obj2;        return [per11.name compare:per22.name];    }];    for (Person *per in marr) {        NSLog(@"%@",per.name);    }

结果

2015-07-28 19:38:59.851 OC10_Block[1347:91927] cunmou2015-07-28 19:38:59.852 OC10_Block[1347:91927] liushanshan2015-07-28 19:38:59.852 OC10_Block[1347:91927] wuhe2015-07-28 19:38:59.852 OC10_Block[1347:91927] yanglin

补充

主函数之前

//    //C语言的函数//    NSInteger maxValue(NSInteger a,NSInteger b){//        return a > b ? a : b;//    }void test1(){    NSLog(@"今天真热");}int addNum(int a,int b){    return a+b;}typedef int DT;//新的类型写在*的后面,就是这里的PFUNtypedef int (*PFUN)(int ,int ) ;typedef NSString *(^Block)(NSArray *) ;//有返回值,无参数typedef NSInteger(^TestBlock)();

////  BaseModel.h//  OC10_Block////  Created by dllo on 15/7/28.//  Copyright (c) 2015年 zhozhicheng. All rights reserved.//#import <Foundation/Foundation.h>@interface BaseModel : NSObject@property(nonatomic,copy)NSString *name;@property(nonatomic,copy)NSString *sex;-(id)initWithName:(NSString *)name              sex:(NSString *)sex;+(id)baseWithName:(NSString *)name              sex:(NSString *)sex;@end

////  BaseModel.m//  OC10_Block////  Created by dllo on 15/7/28.//  Copyright (c) 2015年 zhozhicheng. All rights reserved.//#import "BaseModel.h"@implementation BaseModel-(id)initWithName:(NSString *)name              sex:(NSString *)sex{    self=[super init];    if (self) {        self.name=name;        self.sex=sex;    }return self;}+(id)baseWithName:(NSString *)name              sex:(NSString *)sex{    //多态方式完成    id obj =[[[self class] alloc] initWithName:name sex:sex];    return obj;}@end