构造方法

person.h

#import <Foundation/Foundation.h>@interface Person : NSObject@property int age;@property id obj;@end

person.m

#import "Person.h"@implementation Person@end

main函数

int main(int argc, const char * argv[]){    @autoreleasepool {        Person *p = [Person new];        //[p fsdfdsfd];                NSObject *o = [Person new];                        // id  == NSObject *        // 万能指针，能指向\操作任何OC对象        id d = [Person new];                [d setAge:10];                [d setObj:@"321423432"];                NSLog(@"%d", [d age]);    }    return 0;}