#import <Foundation/Foundation.h>

@interface Person : NSObject
{
    @public
    NSString *_name;
    BOOL _gender;
    @private
    NSInteger _age;
    CGFloat _height;
    CGFloat _weight;
}
-(id)init;
-(instancetype)initWithName:(NSString*)name andGender:(BOOL)gender;
-(NSInteger)adder:(NSInteger)x :(NSInteger)y;
 
-(void)setName:(NSString *)name;
-(void)setAge:(NSInteger)age;
-(void)setName:(NSString *)name andAge:(NSInteger)age;
-(void)setName:(NSString *)name :(NSInteger)age;
+(void)eat;
-(void)sing;
-(void)printInfo;
@end

@implementation Person
-(id)init{
    _name=@"王五";
    _gender=NO;
    _age = 18;
    _height 
 
= 1.80;
    _weight = 78;
    return self;
}
-(instancetype)initWithName:(NSString *)name andGender:(BOOL)gender{
    _name = name;
    _gender = gender;
    return self;
}
-(NSInteger)adder:(NSInteger)x :(NSInteger)y{
    NSLog(@"%ld",x+y);
    return x+y;
}
+(void)eat{
    NSLog(@"吃吃吃...");
}
-(void
 
)sing{
    NSLog(@"唱唱唱...");
}
-(void)setName:(NSString *)name{
    _name = name;
}
-(void)setAge:(NSInteger)age{
    _age = age;
}
-(void)setName:(NSString *)name andAge:(NSInteger)age{
    _name = name;
    _age = age;
}
-(void)setName:(NSString *)name :(NSInteger)age{
    _name = name;
    _age = age;
}
-(void)printInfo{
    NSLog(@"name:%@, gender:%@, age:%ld, height:%.2f, weight:%.2f",_name, _gender?@"female":@"male",
          _age, _height, _weight);
}
@end

int main(int argc, const char * argv[]) {
    Person *person1 = [[Person alloc]initWithName:@"張三" andGender:0];
    [person1 printInfo];
    [person1 sing];
    Person *person2 = [[Person alloc]init];
    [person2 printInfo];
    [Person eat];
        return 0;
}

注意：

1. 類的定義一般寫在.h標頭檔案中，類中函式的實現可以在.m檔案中個性化實現。

2. 靜態函式是所有類物件共有的一個函式，只佔用一個函式空間，可通過類名呼叫。

3. 類的init方法是初始化方法，類的例項化和c++很像，都是呼叫構造方法來實現對例項的初始化。

4. +表示靜態函式，-表示動態函式

輸出為：