oc学习笔记2 点语法

#import <Foundation/Foundation.h>

@interface Dog : NSObject
{
    int _ID;
    NSString *_name;
    int _age;
    float _price;
}
//凡是用initXXX开头的都是构造函数
//init方法实际上没有什么特别的，只是遵循命名约定的普通方法
-(id)init;
-(id)initWithID:(int)newID;
-(id)initWithID:(int)newID andAge:(int)newAge;
-(id)initWithID:(int)newID andAge:(int)newAge andPrice:(int)newPrice;
@property int ID;
@property NSString *name;
@property int age;
@property float price;
@end

#import "Dog.h"

@implementation Dog
-(id)init
{
    return [self initWithID:1001];

}
-(id)initWithID:(int)newID
{
    return [self initWithID:newID andAge:20];
}
-(id)initWithID:(int)newID andAge:(int)newAge
{
    return [self initWithID:newID andAge:newAge andPrice:80.0];
}
-(id)initWithID:(int)newID andAge:(int)newAge andPrice:(int)newPrice
{
    self=[super init];
    if(self){
        _ID=newID;
        _age=newAge;
        _price=newPrice;
    }
    return self;
}

@synthesize ID=_ID;
@synthesize name=_name;
@synthesize age=_age;
@synthesize price=_price;

@end

#import <Foundation/Foundation.h>
#import "Dog.h"
#import "NSString+ReverseString.h"
#import "Person.h"

int main(int argc, const char * argv[])
{

    @autoreleasepool {
        Dog *dog1=[[Dog alloc ] init];
        dog1.name=@"syj";
        NSLog(@"%@",[dog1 name]);
        [dog1 setName:@"ldusyj"];
        NSLog(@"%@",dog1.name);
    }
    return 0;
}

dog1.name=@"syj";

[dog1 setName:@"syj"];

NSLog(@"%@",dog1.name);

NSLog(@"%@",[dog1 name]);

-(void)setAge:(int)newAge 
{ 
    NSLog(@"调用了setAge方法：%i",newAge); 
    self.age = newAge; 
}

-(int)age 
{ 
    NSLog(@"调用了age方法：%i",_age); 
    return self.age; 
}