Objective-C - @property与@synthesize

@property与@synthesize

@interface Person : NSObject
{
    int _age;
    // int age;

    int _height;

    double _weight;

    NSString *_name;
}

// @property：可以自动生成某个成员变量的setter和getter声明
@property int age;
//- (void)setAge:(int)age;
//- (int)age;

@property int height;
//- (void)setHeight:(int)height;
//- (int)height;

- (void)test;

@property double weight;

@property NSString *name;

@end

#import "Person.h"

@implementation Person

// @synthesize自动生成age的setter和getter实现，并且会访问_age这个成员变量
@synthesize age = _age;

@synthesize height = _height;

@synthesize weight = _weight, name = _name;

@end

车类

#import <Foundation/Foundation.h>

@interface Car : NSObject
{
    //int _speed;
    //int _wheels;
}
@property int speed;
@property int wheels;

//@property int speed, wheels;
- (void)test;
@end

#import "Car.h"

@implementation Car
//@synthesize speed = _speed, wheels = _wheels;
// 会访问_speed这个成员变量，如果不存在，就会自动生成@private类型的_speed变量
@synthesize speed = _speed;
@synthesize wheels = _wheels;

- (void)test
{
    NSLog(@"速度=%d", _speed);
}

@end

狗类

@interface Dog : NSObject
@property int age;
@end

#import "Dog.h"

@implementation Dog

- (void)setAge:(int)age
{

}

//- (int)age
//{
//
//}

//- (int)age
//{
//    return 10;
//}

@end

猫类

@interface Cat : NSObject
{
    //int _age;
    //int age;
}
@property int age;
@end

@implementation Cat

// 默认会访问age这个成员变量，如果没有age，就会自动生成@private类型的age变量
@synthesize age;

@end