day04-02-description

Objective-c

//  main.m
//  day04-02-description
//
//  Created by Aaron on 15/7/6.
//  Copyright (c) 2015年 Aaron. All rights reserved.
//
#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Person *p = [[Person alloc] init];
        NSLog(@"%p",p);
        NSLog(@"%@",p);
        NSLog(@"%@",[p description]);
        //NSNumber 作为介质来将基本类型转为对象类型或者将对象类型转为基本类型
        NSNumber *num1 = [NSNumber numberWithInt:10];
        int num2 = [num1 intValue];
        NSLog(@"num2--->%d",num2);
        NSLog(@"%@",num1);
        BOOL rec = [num1 boolValue];
        NSLog(@"%d",rec);
    }
    return 0;
}

#import <Foundation/Foundation.h>
@interface Person : NSObject
{
    NSString *_name;
    NSInteger _age;
}
@end

#import "Person.h"
@implementation Person
-(instancetype)init
{
    if(self = [super init])
    {
        _name = @"蜡笔小新";
        _age = 3;
    }
    return self;
}
-(NSString *)description
{
    return [NSString stringWithFormat:@"%@的年龄是%ld",_name,_age];
}
@end