left of '->next' must point to struct/union为什么？

[nichothia]

这是我的一个学生成绩管理系统的创建链表记录部分 为什么编译器一直说我Student不能illegal use呢？

我明明定义了结构体Student的啊

还有为什么一直说->next左边的不是结构体呢？CurrentData也是我定义过的Student结构体指针啊

跪求解释error和warning的原因

代码如下

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

struct stud
{
	char Name[20];
	float Score;
	struct stud*next;
};
typedef struct stud Student;

Student* Create();


Student* Insert(Student*head);



void Display_Main_Menu();

int menu_select();

int Continue();





int main(int argc,char*argv[])
{

	Display_Main_Menu();

	for(;;)
	{
		switch(menu_select())
		{
		case 1:
			printf("Execution of \"Creat List\"\n");
			Create();
			break;

		default:
			printf("error!please input 1\n");
		};
	}


	return 0;
}

int menu_select()
{
	int SelectedNumber;
	printf("please input the number(from 0 to 7) and \'Enter\':");
	scanf("%d",&SelectedNumber);
	return SelectedNumber;
};

void Display_Main_Menu()
{
	printf("1.  Creat List\n");
	printf("2.  Display All Record\n");
	printf("3.  Insert a Record\n");
	printf("4.  Delete a Record\n");
	printf("5.  Query\n");
	printf("6.  Add Records from a Text File\n");
	printf("7.  Write to a Text File\n");
	printf("0.  Quit\n");
	printf("Give your choice(0-7): ");
};

int Continue() 
{
	char choice;
	printf("continue to input? press \'y\' or \'n\':  ");
	scanf("%c",&choice);
	if(choice=='y')
		return 1;
}

Student* Insert(Student*head)
{
	Student* NewData=(struct Stud*)malloc(sizeof(struct stud));

	printf("please input a name and \'Enter\': ");
	scanf("%s",NewData->Name);

	printf("please input the score and \'Enter\': ");
	scanf("%d",&(NewData->Score));
	NewData->next=NULL;

	if(head==NULL)
	{
		head=NewData;
		return head;
	}

	Student *CurrentData=head;

	while(CurrentData->next!=NULL)
	{
		CurrentData=CurrentData->next;
	};

	CurrentData->next=NewData;

}

Student* Create()
{
	static struct Student *head=NULL;
	do
	{
		Insert(head);
		printf("Insert a piece of data successfully\n");
	}
	while(Continue()==1);

	return head;

}

warning C4133: 'initializing' : incompatible types - from 'struct Stud *' to 'struct stud *'
error C2275: 'Student' : illegal use of this type as an expression
see declaration of 'Student'
error C2065: 'CurrentData' : undeclared identifier
error C2223: left of '->next' must point to struct/union
error C2223: left of '->next' must point to struct/union
error C2223: left of '->next' must point to struct/union
warning C4133: 'function' : incompatible types - from 'struct Student *' to 'struct stud *'
warning C4133: 'return' : incompatible types - from 'struct Student *' to 'struct stud *'
执行 cl.exe 时出错.

[nichothia]

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

struct stud
{
	char Name[20];
	float Score;
	struct stud*next;
};
typedef struct stud Student;

Student* Create();


Student* Insert(Student*head);



void Display_Main_Menu();

int menu_select();

int Continue();





int main(int argc,char*argv[])
{

	Display_Main_Menu();

	for(;;)
	{
		switch(menu_select())
		{
		case 1:
			printf("Execution of \"Creat List\"\n");
			Create();
			break;

		default:
			printf("error!please input 0-5\n");
		};
	}


	return 0;
}

int menu_select()
{
	int SelectedNumber;
	scanf("%d",&SelectedNumber);
	return SelectedNumber;
};

void Display_Main_Menu()
{
	printf("1.  Creat List\n");
	printf("2.  Display All Record\n");
	printf("3.  Insert a Record\n");
	printf("4.  Delete a Record\n");
	printf("5.  Query\n");
	printf("6.  Add Records from a Text File\n");
	printf("7.  Write to a Text File\n");
	printf("0.  Quit\n");
	printf("Give your choice(0-7): ");
};

int Continue() 
{
	char choice;
	printf("continue to input? press \'y\' or \'n\':  ");
	scanf("%c",&choice);
	if(choice=='y')
		return 1;
}

Student* Insert(Student*head)
{
	Student* NewData=(Student*)malloc(sizeof(Student));
	Student *CurrentData=head;

	printf("please input a name and \'Enter\': ");
	scanf("%s",NewData->Name);

	printf("please input the score and \'Enter\': ");
	scanf("%d",&(NewData->Score));
	NewData->next=NULL;

	if(head==NULL)
	{
		head=NewData;
		return head;
	}


	while(CurrentData->next!=NULL)
	{
		CurrentData=CurrentData->next;
	};

	CurrentData->next=NewData;
	return head;

}

Student* Create()
{
	static Student *head=NULL;
	do
	{
		Insert(head);
		printf("Insert a piece of data successfully\n");
	}
	while(Continue()==1);

	return head;

}

根据8楼的提议改好了 虽然编译没错误了有个
warning C4715: 'Continue' : not all control paths return a value
但是运行后Insert了一条记录后 程序直接重复Insert函数 而跳过continue to input? press y or n:的判断 为什么呢？

[cattycat]

typedef struct stud
{
char Name[20];
float Score;
struct stud*next;
}Student;

把你的结构体定义改一下吧

[yzx714]

引用我小学老师的一句话送给楼主:
你眼睛焊桐子壳了？？？
作为老师，你真失败

[nichothia]

汗 我是学生好不好。。。我在帮我同学做C语言的课程设计 从没写过链表边看书编写的 OK??
难道写个学生成绩管理的程序就是老师？ 就你这个逻辑也能在这里帮别人解决问题？？？？？

[pengzhixi]

Student* Insert(Student*head)
{
    Student* NewData=(Student*)malloc(sizeof(Student));//mark

    printf("please input a name and \'Enter\': ");
    scanf("%s",NewData->Name);

    printf("please input the score and \'Enter\': ");
    scanf("%d",&(NewData->Score));
    NewData->next=NULL;

    if(head==NULL)
    {
        head=NewData;
        return head;
    }

    Student *CurrentData=head;

    while(CurrentData->next!=NULL)
    {
        CurrentData=CurrentData->next;
    };

    CurrentData->next=NewData;

}

Student* Create()
{
    static Student *head=NULL;//mark
    do
    {
        Insert(head);
        printf("Insert a piece of data successfully\n");
    }
    while(Continue()==1);

    return head;

}

[huanmie_09]

Student* Insert(Student*head)
{
Student* NewData=(struct Stud*)malloc(sizeof(struct stud));
注意大小写.

Student* Create()
{
static struct Student *head=NULL;

typedef struct stud Student;
这样定义了结构体的同义词后，要么用struct stud, 要么用Student来表示结构体类型.

[KBTyanhuo]

若你真是老师，请不要用“跪”字
大家都是从学生过来的，看到老师这样，会伤心...

[Walf_ghoul]

[Quote=引用 3 楼 kbtyanhuo 的回复:]
若你真是老师，请不要用“跪”字
大家都是从学生过来的，看到老师这样，会伤心...
[/Quote]
只不过一个学生成绩管理系统而已，用不着这样吧...（又不是老师，汗）

[nichothia]

4楼说的在理！

[nichothia]

多谢二楼指点 但是我全都修改成 Student后

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

struct stud
{
	char Name[20];
	float Score;
	struct stud*next;
};
typedef struct stud Student;

Student* Create();


Student* Insert(Student*head);



void Display_Main_Menu();

int menu_select();

int Continue();





int main(int argc,char*argv[])
{

	Display_Main_Menu();

	for(;;)
	{
		switch(menu_select())
		{
		case 1:
			printf("Execution of \"Creat List\"\n");
			Create();
			break;

		default:
			printf("error!please input 0-5\n");
		};
	}


	return 0;
}

int menu_select()
{
	int SelectedNumber;
	printf("please input the number(from 0 to 7) and \'Enter\':");
	scanf("%d",&SelectedNumber);
	return SelectedNumber;
};

void Display_Main_Menu()
{
	printf("1.  Creat List\n");
	printf("2.  Display All Record\n");
	printf("3.  Insert a Record\n");
	printf("4.  Delete a Record\n");
	printf("5.  Query\n");
	printf("6.  Add Records from a Text File\n");
	printf("7.  Write to a Text File\n");
	printf("0.  Quit\n");
	printf("Give your choice(0-7): ");
};

int Continue() 
{
	char choice;
	printf("continue to input? press \'y\' or \'n\':  ");
	scanf("%c",&choice);
	if(choice=='y')
		return 1;
}

Student* Insert(Student*head)
{
	Student* NewData=(Student*)malloc(sizeof(Student));

	printf("please input a name and \'Enter\': ");
	scanf("%s",NewData->Name);

	printf("please input the score and \'Enter\': ");
	scanf("%d",&(NewData->Score));
	NewData->next=NULL;

	if(head==NULL)
	{
		head=NewData;
		return head;
	}

	Student *CurrentData=head;

	while(CurrentData->next!=NULL)
	{
		CurrentData=CurrentData->next;
	};

	CurrentData->next=NewData;

}

Student* Create()
{
	static Student *head=NULL;
	do
	{
		Insert(head);
		printf("Insert a piece of data successfully\n");
	}
	while(Continue()==1);

	return head;

}

还是有

这些错误 为什么呢？
error C2275: 'Student' : illegal use of this type as an expression
see declaration of 'Student'
error C2065: 'CurrentData' : undeclared identifier
error C2223: left of '->next' must point to struct/union
error C2223: left of '->next' must point to struct/union
error C2223: left of '->next' must point to struct/union

[pengzhixi]

我这编译OK了

[huanmie_09]

[Quote=引用 6 楼 nichothia 的回复:]
多谢二楼指点 但是我全都修改成 Student后

C# code

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

struct stud
{
char Name[20];
float Score;
struct stud*next;
};
typedef struct stu……
[/Quote]
Student* Insert(Student*head)
{
Student* NewData=(Student*)malloc(sizeof(Student));

printf("please input a name and \'Enter\': ");
scanf("%s",NewData->Name);

printf("please input the score and \'Enter\': ");
scanf("%d",&(NewData->Score));
NewData->next=NULL;

if(head==NULL)
{
head=NewData;
return head;
}

Student *CurrentData=head;
把红色那一句移动到
Student* Insert(Student*head)
{
Student* NewData=(Student*)malloc(sizeof(Student));
这里就ok了.
c编译器的原因，变量声明放在前面.
或者改成.cpp文件也可以.

[yzx714]

[Quote=引用 12 楼 nichothia 的回复:]
这是我的一个学生成绩管理系统
[/Quote]你这句话实在太让人误解了。。。

[nichothia]

好吧 是我说的有歧义 可是 你能帮我把这个问题解决了么、、、？