Objective-C - self用法详解

self的用途

/*
 self的用途：
 1> 谁调用了当前方法，self就代表谁
 * self出现在对象方法中，self就代表对象
 * self出现在类方法中，self就代表类

 2> 在对象方法利用"self->成员变量名"访问当前对象内部的成员变量

 2> [self 方法名]可以调用其他对象方法\类方法
 */

@interface Dog : NSObject
- (void)bark;
- (void)run;
@end

@implementation Dog
- (void)bark
{
    NSLog(@"汪汪汪");
}
- (void)run
{
    [self bark];
    //NSLog(@"汪汪汪");
    NSLog(@"跑跑跑");
}
@end

int main()
{
    Dog *d = [Dog new];

    [d run];

    return 0;
}

self ->person类

@interface Person : NSObject
{
    int _age;
}

- (void)setAge:(int)age;
- (int)age;

- (void)test;

@end

@implementation Person
- (void)setAge:(int)age
{
    // _age = age;
    self->_age = age;
}
- (int)age
{
    return self->_age;
}

- (void)test
{
    // self：指向了方向调用者,代表着当期对象
    int _age = 20;
    NSLog(@"Person的年龄是%d岁", self->_age);
}

@end

int main()
{
    Person *p = [Person new];

    [p setAge:10];

    [p test];

    return 0;
}

self引发死循环的注意点

@interface Person : NSObject
- (void)test;
+ (void)test;

- (void)test1;
+ (void)test2;


- (void)haha1;

+ (void)haha2;


@end

@implementation Person
- (void)test
{
    NSLog(@"调用了-test方法");

    // 会引发死循环
    //[self test];
}

+ (void)test
{
    NSLog(@"调用了+test方法");

    // 会引发死循环
    //[self test];
}

- (void)test1
{
    [self test]; // -test
}

+ (void)test2
{
    [self test]; // +test
}

- (void)haha1
{
    NSLog(@"haha1-----");
}


void haha3()
{

}

+ (void)haha2
{
    // haha3();
    [self haha3];
    // [self haha1];
}
@end

int main()
{
    [Person haha2];
    //Person *p = [Person new];

    //[p test1];
    return 0;
}