继承 初始化方法 遍历构造器

继承:

1.单向继承,一个类只能有一个父类,一个父类可以有多个子类.

2.单向继承,基类(根类)是OSObject

3.子类可以继承父类的属性和方法

 

当父类的方法不满足子类的需求时,子类可以重写父类的方法,重写父类的方法,在子类中不需要再次声明.

1.完全重写

2.部分重写 使用super

 

建立继承关系之后,子类可以继承父类的:

1.实例变量,@public@protected修饰情况之下

2.公开的方法

一个方法如果在.h中声明了,那么这个方法就是公开的方法,如果没有声明,则是私有的.

OC中没有绝对私有的方法.

 

子类调用方法的过程:

先在本类中寻找方法,如果找到就直接调用,如果没有找到就在其父类中寻找,如果在父类中也没有找到,就继续其次向上寻找(父类的父类),直到找到为止.

如果找不到就抛出异常,引起crash.

 

对象对对象可以赋值,对象就是指针.

 

自定义初始化方法不需要在.h文件中声明.因为是重写了该方法.

 

 

 

遍历构造器一定是一个类方法

返回值类型(id,instancetype)

 

 都是声明变量 自定义减号需要声明变量 遍历构造器加号 不需要声明变量

自定义初始化方法:初始化+赋值.

便利构造器:开辟空间+初始化+赋值.

 

自定义初始化方法:

 

 

-(id)initWithColor:(NSString *)color

price:(NSString *)price{

if (self=[super init]) {

_price = price;

_color = color;

}

return self;

}

便利构造器:

 

 

+(id)appleWithColor:(NSString *)color

price:(NSString *)price{

Apple *apple=[[Apple alloc]initWithColor:color price:price];

return apple;

}

 

您好，写一个简单地便利构造器+(Student *)studntWithName :(NSString *)aName  andAge:(int)anAge{ Student *stu=[Student  alloc]initWithName :aName  andAge:anAgereturn stu;}//1..h声明文件中#import <Foundation/Foundation.h>@interface Person :NSObject{    NSString * name;//名字    int age;//年龄    }@property (assign,nonatomic) NSString * name;//声明名字访问属性@property (assign,nonatomic) int age;//声明年龄访问属性-(id)initWith:(NSString *)newName  withAge:(int)newAge;//声明构造函数-(void)sayhi;//打招呼方式@end//2..m实现文件中@implementation Person@synthesize name;//实现name属性@synthesize age;//实现age属性-(id)initWith:(NSString *)newName  withAge:(int)newAge;//实现构造函数{    self =[super init];//调用父类super init方法    if(self)    {        [self setName:newName];另一种调用方法 self.name:newName;        [self setAge:newAge];//另一种调用方法 self.Age:newAge;    }    return self;/*构造函数一般书写方式:    self =[super init];    if(self)    {　　　　函数体    }    return self;*/} -(void)sayhi{    NSLog(@"hi,My name is %@,I'm %d old!",name,age);}@end //3.主函数中#import <Person.h> int main(int argc, const char * argv[]){    Person * xiaozhang=[[Person alloc]initWith:@"小张" withAge:25];//构造函数调用    [xiaozhang sayhi];//调用sayhi方法    return 0;}

写一个简单地便利构造器

+(Student *)studntWithName :(NSString *)aName  andAge:(int)anAge{ Student *stu=[Student  alloc]initWithName :aName  andAge:anAgereturn stu;}//1..h声明文件中#import <Foundation/Foundation.h>@interface Person :NSObject{    NSString * name;//名字    int age;//年龄    }@property (assign,nonatomic) NSString * name;//声明名字访问属性@property (assign,nonatomic) int age;//声明年龄访问属性-(id)initWith:(NSString *)newName  withAge:(int)newAge;//声明构造函数-(void)sayhi;//打招呼方式@end//2..m实现文件中@implementation Person@synthesize name;//实现name属性@synthesize age;//实现age属性-(id)initWith:(NSString *)newName  withAge:(int)newAge;//实现构造函数{    self =[super init];//调用父类super init方法    if(self)    {        [self setName:newName];另一种调用方法 self.name:newName;        [self setAge:newAge];//另一种调用方法 self.Age:newAge;    }    return self;/*构造函数一般书写方式:    self =[super init];    if(self)    {　　　　函数体    }    return self;*/} -(void)sayhi{    NSLog(@"hi,My name is %@,I'm %d old!",name,age);}@end //3.主函数中#import <Person.h> int main(int argc, const char * argv[]){    Person * xiaozhang=[[Person alloc]initWith:@"小张" withAge:25];//构造函数调用    [xiaozhang sayhi];//调用sayhi方法    return 0;}

//初始化方法

    //形式:

    //系统的:- (instanceType)init;

    //自定义的: - (instanceType)initWithXXX(参数类型)参数名......

//    Zombie *zombie = [[Zombie alloc]

//                      initWithName:@"wuye"  hp:20 ap:2 speed:10];

//    NSLog(@"%@", zombie.name);

    

 //[zombie setName:@"wuye" ap:20 hp:2 speed:1];

    //遍历构造器

    //+ (instanceType)类名;

    //+ (instanceType)类名WithXXX:(参数类型)参数......

    BlockZombie *z = [BlockZombiezombie];

    z.name =@"zahngyang";

自定义初始化方法

#import <Foundation/Foundation.h>

@interface Zombie : NSObject

{

    NSInteger _hp;//血量

    NSInteger _ap;//攻击力

    CGFloat _speed;//速度

    NSString *_name;//名字

}

- (void)move;//移动

- (void)attack;//攻击

- (void)die;//死亡

-(void)setName:(NSString *)name;

- (NSString *)name;

- (void)setSpeed:(CGFloat )speed;

- (CGFloat )speed;

- (void)setAp:(NSInteger )ap;

- (NSInteger )ap;

- (void)setHp:(NSInteger )hp;

- (NSInteger )hp;

- (instancetype)initWithName:(NSString *)name;

- (instancetype)initWithName:(NSString *)name hp:(NSString *)hp ap:(NSInteger )ap speed:(CGFloat )speed;

@end

#import "Zombie.h"

@implementation Zombie

//自定义初始化方法

- (instancetype)initWithName:(NSString *)name;

{

    //1.调用从父类继承的init方法,作用:初始化从父类继承的成员变量

   self = [superinit];

    //2.self是否为空,

     if (self) {

    //3.如果self不是空,就给成员变量赋值

    _name = name;

 }

//4.

  return self;

}

- (instancetype)initWithName:(NSString *)name hp:(NSInteger )hp ap:(NSInteger )ap speed:(CGFloat )speed

{

    self = [superinit];

    if (self) {

        _name = name;

        _hp = hp;

        _ap = ap;

        _speed = speed;

    }

    return self;

}

- (void)move

{

    NSLog(@"fast");

}

- (void)attack

{

    NSLog(@"strong");

}

- (void)die

{

    NSLog(@"fast");

}

-(void)setName:(NSString *)name

{

    _name = name;

}

- (NSString *)name

{

    return _name;

}

- (void)setSpeed:(CGFloat )speed

{

    _speed = speed;

}

- (CGFloat )speed

{

    return _speed;

    

}

- (void)setAp:(NSInteger )ap

{

    _ap = ap;

}

- (NSInteger )ap

{

    return _ap;

}

- (void)setHp:(NSInteger )hp

{

    _hp = hp;

}

- (NSInteger )hp

{

    return _hp;

}

@end

建一个student类

#import <Foundation/Foundation.h>

@interface Student : NSObject

@property NSString *name;

@property NSInteger age;

@property NSInteger number;

@property NSString *gender;

@property CGFloat score;

- (instancetype)initWithName:(NSString *)name Gender:(NSString *)gender Number:(NSInteger )number Age:(NSInteger )age Score:(CGFloat )score;

+ (instancetype)studentWithName:(NSString *)name Gender:(NSString *)gender Number:(NSInteger )number Age:(NSInteger )age Score:(CGFloat )score;

@end

#import "Student.h"

@implementation Student

- (instancetype)initWithName:(NSString *)name Gender:(NSString *)gender Number:(NSInteger )number Age:(NSInteger )age Score:(CGFloat )score

{

    self = [superinit];//self继承父类super初始化

    if (self) {//如果继承完成以下

        self.name = name;

        self.gender = gender;

        self.number = number;

        self.age = age;

        self.score = score;

    }

    return self;

}

+ (instancetype)studentWithName:(NSString *)name Gender:(NSString *)gender Number:(NSInteger )number Age:(NSInteger )age Score:(CGFloat )score

{

    Student *s = [[Studentalloc] initWithName:nameGender:gender Number:numberAge:age Score:score];

    return s;

}

@end