5.利用前面的成绩类，重新设计一个学生类

1> 属性

* 姓名

* 学号

* 成绩（包括3科成绩）

2> 行为

* 比较C语言成绩：跟另外一个学生比较C语言成绩，返回成绩差（自己的成绩 - 其他人的成绩）

* 比较OC成绩：跟另外一个学生比较OC语言成绩，返回成绩差（自己的成绩 - 其他人的成绩）

* 比较iOS成绩：跟另外一个学生比较iOS语言成绩，返回成绩差（自己的成绩 - 其他人的成绩）

* 比较总分：跟另外一个学生比较总分，返回成绩差（自己的成绩 - 其他人的成绩）

* 比较平均分：跟另外一个学生比较平均分，返回成绩差（自己的成绩 - 其他人的成绩）

*/

#import <Foundation/Foundation.h>

@interface Score : NSObject

{

@public

    int CScore;

    int OCScore;

    int IOSScore;

}

@end

@implementation Score

@end

@interface Student : NSObject

{

    @public

    char* name;

    char* number;

    Score* score;

}

- (int) compareCScoreWithOther:(Student*) student;

@end

@implementation Student

- (int) compareCScoreWithOther:(Student*) student

{

    return score->CScore - student->score->CScore;

}

@end

int main()

{

    Student * stu1 = [Student new];

    Student * stu2 = [Student new];

    stu1->score->CScore = 100;

    stu2->score->CScore = 200;

    int a = [stu1 compareCScoreWithOther:stu2];

    NSLog(@"%d",a);

    return 0;

}

这是我写的，编译连接可以，但是运行时提示：Segmentation fault: 11
求大神指点！

问题已解决！

#import <Foundation/Foundation.h>

@interface Score : NSObject

{

@public

    int CScore;

    int OCScore;

    int IOSScore;

}

- (int) compareCScoreWithOther:(Score *) score;

@end

@implementation Score

- (int) compareCScoreWithOther:(Score *) score

{

    return CScore - score->CScore;

}

@end

@interface Student : NSObject

{

    @public

    char* name;

    char* number;

    Score* score;

}

- (int) compareCScoreWithOther:(Student*) student;

@end

@implementation Student

- (int) compareCScoreWithOther:(Student*) student

{

    return [score compareCScoreWithOther:student->score];

}

@end

int main()

{

    Student * stu1 = [Student new];

    Student * stu2 = [Student new];

    Score * score1 = [Score new];

    Score * score2 = [Score new];

    score1->CScore = 100;

    score2->CScore = 200;

    stu1->score = score1;

    stu2->score = score2;

    //stu1->score->CScore = 100;//第二层是结构体可以，如果是对象，好像只能间接赋值，如上四句

    //stu2->score->CScore = 200;

    int a = [stu1 compareCScoreWithOther:stu2];

    NSLog(@"%d",a);

    return 0;

}

怎么会有表情符号！:(

完善版

#import <Foundation/Foundation.h>

@interface Score : NSObject

{

@public

    int CScore;

    int OCScore;

    int IOSScore;

}

- (int) compareCScoreWithOther:(Score *) score;

- (int) compareSumScoreWithOther:(Score *)score;

@end

@implementation Score

- (int) compareCScoreWithOther:(Score *) score

{

    return CScore - score->CScore;

}

- (int) compareSumScoreWithOther:(Score *)score

{

    int sum1 = CScore + OCScore + IOSScore;

    int sum2 = score->CScore + score->OCScore + score->IOSScore;

    return sum1 - sum2;

}

@end

@interface Student : NSObject

{

    @public

    char* name;

    char* number;

    Score* score;

}

- (int) compareCScoreWithOther:(Student*) student;

- (int) compareSumScoreWithOther:(Student*) student;

@end

@implementation Student

- (int) compareCScoreWithOther:(Student*) student

{

    return [score compareCScoreWithOther:student->score];

}

- (int) compareSumScoreWithOther:(Student*) student

{

    return [score compareSumScoreWithOther:student->score];

}

@end

int main()

{

    Student * stu1 = [Student new];

    Student * stu2 = [Student new];

    Score * score1 = [Score new];

    Score * score2 = [Score new];

    score1->CScore = 100;

    score2->CScore = 200;

    stu1->score = score1;

    stu2->score = score2;

    //stu1->score->CScore = 100;//第二层是结构体可以，如果是对象，好像只能间接赋值，如上

    //stu2->score->CScore = 200;

    int a = [stu1 compareCScoreWithOther:stu2];

    int b = [stu1 compareSumScoreWithOther:stu2];

    NSLog(@"%d",a);

    return 0;

}