創建類：User

當我們使用@property 創建屬性的時候，會產生“.語法”
--> 使用“.”代替set 和 get 完成設置器和訪問器的工作

User.h

#import <Foundation/Foundation.h>
@interface User : NSObject

@property(nonatomic,copy)NSString *username;
@property(nonatomic,assign)NSInteger password;

@end

User.m

#import "User.h"
@implementation User

@end

main.m

#import <Foundation/Foundation.h>
#import "User.h"

int main(int argc, const char *argv[])
{
  @autoreleasepool
  {
    //1.創建
    User *user1 = [[User alloc]init];

    //2.賦值
    [user1 setUsername:@"123@163.com"];
    [user1 setPassword:1234];

    //3.取值
    NSLog(@"用戶名：%@",[user1 username]);
    NSLog(@"密碼: %ld",[user1 password]);

/*____________________________________________*/

    //1.創建
    User *user2 = [[User alloc]init];
    
    //2.賦值
    user2.username = @"123@423.com";
    user2.password = 12345;

    //取值
    NSString *user2name = user2.username;
    NSInteger user2pass = user2.password;

    NSLog(@"%@ %ld",user2.username,user2.password);
  }
   return 0;
}