#import <Foundation/Foundation.h>
typedef enum Sex{female,male} sSex;
@interface Student : NSObject
{
    NSString *_name;
    int _age;
    sSex _sex;
    int _grade;
   
   
}
-(void)setName:(NSString *)name;
-(void)setAge:(int)age;
-(void)setSex:(int)sex;
-(void)setGrade:(int)grade;
-(NSString *)getName;
-(int)getAge;
-(int)getSex;
-(int)getGrade;
@end


#import "Student.h"

@implementation Student
-(void)setName:(NSString *)name{

    _name=name;

}
-(void)setAge:(int)age{

    _age=age;

}
-(void)setSex:(int)sex{

    if(sex==1||sex==0){
    _sex=sex;
    }

}
-(void)setGrade:(int)grade{

    if (grade>=0&&grade<=100) {
        _grade=grade;
    }

}
-(NSString *)getName{

    return _name;

}
-(int)getAge{

    return _age;

}
-(int)getSex{

    return _sex;
}
-(int)getGrade{
        
    return _grade;

}

@end


#import <Foundation/Foundation.h>
#import "Student.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool {
   
        Student *ncr=[Student new];
        [ncr setName:@"Nightcrawler"];
        [ncr setAge:21];
        [ncr setSex:male];
        [ncr setGrade:100];
        NSString *name=[ncr getName];
        int age=[ncr getAge];
        int sex=[ncr getSex];
        int grade=[ncr getGrade];
        NSString *ssex;
        if (sex==1) {
            ssex=@"male";
        }else{
            ssex=@"female";
        }
        NSLog(@"姓名:%@,年龄:%d,性别:%@,成绩:%d",name,age,ssex,grade);
    }
    return 0;
}

加油，要是有注释就更好了。