OC语言day04-09构造方法练习

pragma mark 构造方法练习

pragma mark 概念

pragma mark 代码

#import <Foundation/Foundation.h>
#pragma mark 类
#import "Person.h"
#import "Student.h"
#pragma mark main函数
int main(int argc, const char * argv[])
{
#warning 让学生继承人类,要求学生对象初始化之后,年龄是10, 学号是1, 怎么办?
    
//    Person *p = [[Person alloc]init];
//    NSLog(@"P2 = %@",p);
//    Person *p1 = [[Person alloc]init];
//    NSLog(@"P1 = %@",p1);
    
    Student *stu = [[Student alloc]init];
    NSLog(@"%@",stu);
    
    Student *stu1 = [[Student alloc]init];
    NSLog(@"%@",stu1);

    return 0;
}

Person.h //人类 (父类)

#import <Foundation/Foundation.h>

@interface Person : NSObject

@property int age;
@end

Person.m

#import "Person.h"

@implementation Person

- (instancetype)init
{
    if (self = [super init]) {
        // 如果父类 不等于空
        // 初始化 子类
        _age = 10;
    }
    return self;
}


- (NSString *)description
{
    return [NSString stringWithFormat:@"age = %i",_age];
}
@end

---

Student.h // 学生类 (子类)

#import "Person.h"
@interface Student : Person

@property int no; // 学号
@end

Student.m

#import "Student.h"

@implementation Student

- (instancetype)init
{
    if (self = [super init]) {
//        [self setAge:10];
        _no = 10;
    }
    return self;
}


- (NSString *)description
{
    return [NSString stringWithFormat:@"age = %i, no = %i",[self age],[self no]];
}
@end

---