On the compilation of student management system of C language course (simple version)

Curriculum requirements

According to the requirements of course design , We need to add the following functions to our management system ：1, Menu mode works ;2, Input function ;3, Browsing function ;4, Query function ;5, Sorting function ;6, Delete function ;7, Modify the function ;8, Save function .

We will complete the writing step by step with the idea of modularization .

Construction of structure

We already know the requirements of the curriculum , According to the requirements, we can build the following structure ：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define N 30
int n=0;                  // Create global variables to control the number of people entered  
struct student{         // Defining structure  
	char sumber[10];    // Student number  
	char name[15];          // full name  
	int age;            // Age  
	char gender;        // Gender  
	char birthday;      // date of birth  
	char site;          // Address  
	int sum;        // Phone number  
	char mail;          // email  
	
}stu[N];

After building the structure , We will write module words for functions ;

menu

The first is the preparation of the menu ：

void show()			 // Show menu  
{
	printf("     ----------1. Enter student information ----------\n");
	printf("     ----------2. Search for student information ----------\n");
	printf("     ----------3. Browse student information ----------\n");
	printf("     ----------4. Modify student information ----------\n");
	printf("     ----------5. Save student information ----------\n");
	printf("     ----------6. Delete student information ----------\n");
	printf("     --------------0. sign out --------------\n"); 
}

Use several consecutive outputs to complete the preparation of the menu . 

Enter student information

We use entering function ：

int entering()        // Enter student information 
{
	int a; 
	printf(" Please enter the number of students to add ：");
	scanf("%d",&a);
	int i;
	for(i=n;i<a+n;i++)           // Add to the existing number  
	{
	printf(" Please enter the student number : ");
	scanf("%s", stu[i].sumber);
	printf(" Please enter the student's name : ");
	scanf("%s",&stu[i].name);
	printf(" Please enter the age of the student : ");
	scanf("%d",&stu[i].age);
	printf(" Please enter the gender of the student : ");
	scanf("%s",&stu[i].gender);
	printf(" Please enter the date of birth of the student : ");
	scanf("%s",&stu[i].birthday);
	printf(" Please enter the student's address : ");
	scanf("%s",&stu[i].site);
	printf(" Please enter the student's phone number : ");
	scanf("%d",&stu[i].sum);
	printf(" Please enter the student's email : ");
	scanf("%s",&stu[i].mail);
	printf("\n");
}
	n=n+a;       // Now the number of people in the system  
} 

Browse student information

Use browse function ：

void browse()           // Browse student information  
{
	if(n==0)            // When n by 0 Give a hint when ： No information  
	{
	printf(" There is currently no student information \n");
	return;
	}
	printf(" Student number    full name    Age    Gender    date of birth    Address    Phone number    email \n");
	for(int i=0;i<=n;i++)
	{
		printf("%s  %s  %d  %s  %s  %s  %d  %s", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender, stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
	}
	system("pause");

}

If n=0 Will give a prompt without information ;

Search for student information

Here I use the student ID to search ：

void inquire()          // Search for student information 
{
	char num[10];
	printf(" Please enter your student number ：");
	scanf("%s",&num);
	int i;
	for(i=0;i<n;i++)
	{
	
		if(strcmp(stu[i].sumber, num) == 0)                     // Traverse and query personal information  
		{
		printf(" Student number    full name    Age    Gender    date of birth    Address    Phone number    email ");
		printf("%s  %s  %d  %s  %s  %s  %d  %s", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender, stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
		break; 
	}

		
	}
	if(i==n)
	printf(" Check no one \n"); 
 } 

Save information

void save(){
	int i;
	FILE *fp;
	char filename[16];
	printf(" Please enter a file name to save ：\n");
	scanf("%s", filename);
	fp = fopen(filename, "w");
	for (i = 0; i < n; i++){
		fprintf(fp, "%s%s%d%s%s%s%d%s\n", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender,
			stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
	}
	printf(" Saved successfully ！！！\n");
	fclose(fp);
	system("pause");
}

I don't quite understand this part , If you know something, you can discuss it together .

Delete the information

Use student ID to search , Delete the student number , And move the back position forward .

void del()            // Delete 
{
	int i, j, flag;
	char s1[10];
	printf(" Please enter the student number to be deleted ：\n");
	scanf("%s", s1);
	flag = 0;
	for (i = 0; i < n; i++)
	{
		if (strcmp(s1, stu[i].sumber) == 0)
		{
			flag = 1;
			for (j = i; j < n - 1; j++)
			{
				stu[j] = stu[j + 1];// Just move all the students in the back one  
			}
		}
		if (flag == 1) break;// Indicates that the student to be deleted has been found , End of cycle  
	}
	if (0 == flag)
	{
		printf(" The student number does not exist ！！！\n");
	}

	if (1 == flag)
	{
		printf(" Delete successful \n");
		n--;
	}
	system("pause");

Modify the information

Use the submenu to modify the information of the target .

void remove()         // modify 
{
	int i,g;
	char name[15],number[9],sex,birthday,site,mail;
	int age,sum;
	printf(" Please enter the name of the student to be modified : \n");
	getchar();
	gets(name);
	 
	while(1)
	{
		g=0;
		for(i=0;i<n;i++)
		{
			int num1; 
			if(strcmp(name,stu[i].name)==0)          // Traverse to find information , Create submenu  
			{
				g=1;            
				printf("     ----------  1. Change the student number   ----------\n");
				printf("     ----------  2. Change the name   ----------\n");
				printf("     ----------  3. Change the age   ----------\n");
				printf("     ----------  4. Change gender   ----------\n");
				printf("     ----------5. Modify phone number ----------\n");
				printf("     ----------6. Modify the date of birth ----------\n");
				printf("     ----------  7. Change address   ----------\n");
				printf("     ----------  8. Modify email   ----------\n");
				printf("    ----------  9. Exit the submenu   ----------\n");
			
			printf(" Please enter the service of the submenu ：");
			scanf("%d",&num1);
			switch(num1)                        // Change information  
			{
				case 1:
					printf(" Please enter a new student number ：");
					getchar();
					gets(number);
					strcpy(stu[i].sumber,number);
					break;
					
				case 2:
					printf(" Please enter a new name ：");
					getchar();
					gets(name);
					strcpy(stu[i].name,name);
					break;
					
				case 3:
					printf(" Please enter a new age ：");
					scanf("%d",&age);
					stu[i].age=age;
					break;
					
				case 4:
					printf(" Please enter a new gender ：");
					scanf("%d",&sex);
					stu[i].gender=sex;
					break;
					
				case 5:
					printf(" Please enter a new phone number ：");
					scanf("%d",&sum);
					stu[i].sum=sum;
					break;
				
				case 6:
					printf(" Please enter a new date of birth ：");
					scanf("%s",&birthday);
					stu[i].birthday=birthday;
					break;
				
				case 7:
					printf(" Please enter a new address ：");
					scanf("%d",&site);
					stu[i].site=site;
					break;
				
				case 8:
					printf(" Please enter a new mailbox ：");
					scanf("%d",&mail);
					stu[i].mail=mail;
					break;
					
				case 9:
					return;
					break;
					
				default:
					printf(" Please be there. 1--9 Choose between ！\n");				
			 } 
			}
		}
		if(g==0)
		printf(" Check no one ");
	}
}  

choice

utilize switch Statement to jump to the function used , It is similar to the function of selecting submenu in modification .

void choose(int i)
{
	switch(i){
		case 1:entering();break;
		case 2:inquire();break;
		case 3:browse();break;
		case 4:remove();break;
		case 5:save();break;
		case 6:del();break;
		case 0:return;break; 
		default :printf(" Incorrect input "); 
	}
	
}

Here are all the codes of the management system ：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define N 30
int n=0;                  // Create global variables to control the number of people entered  
struct student{         // Defining structure  
	char sumber[10];    // Student number  
	char name[15];          // full name  
	int age;            // Age  
	char gender;        // Gender  
	char birthday;      // date of birth  
	char site;          // Address  
	int sum;        // Phone number  
	char mail;          // email  
	
}stu[N];


// Defined function 
int entering()        // Enter student information 
{
	int a; 
	printf(" Please enter the number of students to add ：");
	scanf("%d",&a);
	int i;
	for(i=n;i<a+n;i++)           // Add to the existing number  
	{
	printf(" Please enter the student number : ");
	scanf("%s", stu[i].sumber);
	printf(" Please enter the student's name : ");
	scanf("%s",&stu[i].name);
	printf(" Please enter the age of the student : ");
	scanf("%d",&stu[i].age);
	printf(" Please enter the gender of the student : ");
	scanf("%s",&stu[i].gender);
	printf(" Please enter the date of birth of the student : ");
	scanf("%s",&stu[i].birthday);
	printf(" Please enter the student's address : ");
	scanf("%s",&stu[i].site);
	printf(" Please enter the student's phone number : ");
	scanf("%d",&stu[i].sum);
	printf(" Please enter the student's email : ");
	scanf("%s",&stu[i].mail);
	printf("\n");
}
	n=n+a;       // Now the number of people in the system  
} 


void browse()           // Browse student information  
{
	if(n==0)            // When n by 0 Give a hint when , No information  
	{
	printf(" There is currently no student information \n");
	return;
	}
	printf(" Student number    full name    Age    Gender    date of birth    Address    Phone number    email \n");
	for(int i=0;i<=n;i++)
	{
		printf("%s  %s  %d  %s  %s  %s  %d  %s", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender, stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
	}
	system("pause");

}
void inquire()          // Search for student information 
{
	char num[10];
	printf(" Please enter your student number ：");
	scanf("%s",&num);
	int i;
	for(i=0;i<n;i++)
	{
	
		if(strcmp(stu[i].sumber, num) == 0)                     // Traverse and query personal information  
		{
		printf(" Student number    full name    Age    Gender    date of birth    Address    Phone number    email ");
		printf("%s  %s  %d  %s  %s  %s  %d  %s", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender, stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
		break; 
	}

		
	}
	if(i==n)
	printf(" Check no one \n"); 
 } 

void save(){
	int i;
	FILE *fp;
	char filename[16];
	printf(" Please enter a file name to save ：\n");
	scanf("%s", filename);
	fp = fopen(filename, "w");
	for (i = 0; i < n; i++){
		fprintf(fp, "%s%s%d%s%s%s%d%s\n", stu[i].sumber, stu[i].name, stu[i].age, stu[i].gender,
			stu[i].birthday, stu[i].site, stu[i].sum, stu[i].mail);
	}
	printf(" Saved successfully ！！！\n");
	fclose(fp);
	system("pause");
}

void del()            // Delete 
{
	int i, j, flag;
	char s1[10];
	printf(" Please enter the student number to be deleted ：\n");
	scanf("%s", s1);
	flag = 0;
	for (i = 0; i < n; i++)
	{
		if (strcmp(s1, stu[i].sumber) == 0)
		{
			flag = 1;
			for (j = i; j < n - 1; j++)
			{
				stu[j] = stu[j + 1];// Just move all the students in the back one  
			}
		}
		if (flag == 1) break;// Indicates that the student to be deleted has been found , End of cycle  
	}
	if (0 == flag)
	{
		printf(" The student number does not exist ！！！\n");
	}

	if (1 == flag)
	{
		printf(" Delete successful \n");
		n--;
	}
	system("pause");
}           
void remove()         // modify 
{
	int i,g;
	char name[15],number[9],sex,birthday,site,mail;
	int age,sum;
	printf(" Please enter the name of the student to be modified : \n");
	getchar();
	gets(name);
	 
	while(1)
	{
		g=0;
		for(i=0;i<n;i++)
		{
			int num1; 
			if(strcmp(name,stu[i].name)==0)          // Traverse to find information , Create submenu  
			{
				g=1;            
				printf("     ----------  1. Change the student number   ----------\n");
				printf("     ----------  2. Change the name   ----------\n");
				printf("     ----------  3. Change the age   ----------\n");
				printf("     ----------  4. Change gender   ----------\n");
				printf("     ----------5. Modify phone number ----------\n");
				printf("     ----------6. Modify the date of birth ----------\n");
				printf("     ----------  7. Change address   ----------\n");
				printf("     ----------  8. Modify email   ----------\n");
				printf("    ----------  9. Exit the submenu   ----------\n");
			
			printf(" Please enter the service of the submenu ：");
			scanf("%d",&num1);
			switch(num1)                        // Change information  
			{
				case 1:
					printf(" Please enter a new student number ：");
					getchar();
					gets(number);
					strcpy(stu[i].sumber,number);
					break;
					
				case 2:
					printf(" Please enter a new name ：");
					getchar();
					gets(name);
					strcpy(stu[i].name,name);
					break;
					
				case 3:
					printf(" Please enter a new age ：");
					scanf("%d",&age);
					stu[i].age=age;
					break;
					
				case 4:
					printf(" Please enter a new gender ：");
					scanf("%d",&sex);
					stu[i].gender=sex;
					break;
					
				case 5:
					printf(" Please enter a new phone number ：");
					scanf("%d",&sum);
					stu[i].sum=sum;
					break;
				
				case 6:
					printf(" Please enter a new date of birth ：");
					scanf("%s",&birthday);
					stu[i].birthday=birthday;
					break;
				
				case 7:
					printf(" Please enter a new address ：");
					scanf("%d",&site);
					stu[i].site=site;
					break;
				
				case 8:
					printf(" Please enter a new mailbox ：");
					scanf("%d",&mail);
					stu[i].mail=mail;
					break;
					
				case 9:
					return;
					break;
					
				default:
					printf(" Please be there. 1--9 Choose between ！\n");				
			 } 
			}
		}
		if(g==0)
		printf(" Check no one ");
	}
}            
void show()			 // Show menu  
{
	printf("     ----------1. Enter student information ----------\n");
	printf("     ----------2. Search for student information ----------\n");
	printf("     ----------3. Browse student information ----------\n");
	printf("     ----------4. Modify student information ----------\n");
	printf("     ----------5. Save student information ----------\n");
	printf("     ----------6. Delete student information ----------\n");
	printf("     --------------0. sign out --------------\n"); 
}

void choose(int i)
{
	switch(i){
		case 1:entering();break;
		case 2:inquire();break;
		case 3:browse();break;
		case 4:remove();break;
		case 5:save();break;
		case 6:del();break;
		case 0:return;break; 
		default :printf(" Incorrect input "); 
	}
	
}

int main()
{	
	int a;
	show();
	do{
	printf("\n Please enter the service you want to select : ");
	scanf("%d",&a);
	choose(a);
	}while(a);
	return 0;
 } 

You are welcome to correct anything wrong .