How can I print the registration number of student according to his/her department and school

Question

Getting issue while solving this problem for assignment of C programming:

Need to create an app for college where there are 500 undergraduate students from which 250 are in School of Engineering (SOE) and 250 are in School of Science (SOE) , where suppose if a student belongs to Computer engineering (CE) batch 2020_21: supposed output needs too look like: SOEUNGCE0001 - SOEUNGCE0040

departments in school of engineering are:

1. chemical engineering -CHE
2. computer engineering -CE
3. mechanical engineering- ME
4. Environmental engineering -ENE
5. Electrical Engineering - EE

and in school of science:

1. Architecture -AR
2. computer science-CS
3. Biotechnology-BT
4. Pharmacy-PH

I tried printing with switch case statements but it's wasn't working with strings. also the below program is having some issue i.e. it doesn't take some inputs. HELP ME SOLVE THIS.

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

typedef struct{
    char name;
    int roll_no;
    char department;
    char school;
}students;

int main()
{
    students student;

    //inputs
    printf("Enter Name : " );
    scanf("%s", &student.name);
    printf("\nRoll Number : ");
    scanf("%d", &student.roll_no);
    printf("\nDepartment : ");
    scanf("%s",&student.department);
    printf("\nSchool : ");
    scanf("%s",&student.school);

    if (student.department == 'Chemical')
    {
        printf("Name : %s \t",student.name);
        
        printf("\n%sUNG%s00%d", student.school, "CHE", student.roll_no);
    }

    return 0;
}

Answer 1

You have 3 mistakes:

1. Logical Error: since name, department and school are strings, so they must be arrays of characters i.e char name[100]. So the structure should be modified as the following:

typedef struct{          
    char name[100];      
    int roll_no;         
    char department[100];
    char school[100];    
}students;               

2- After editing the structure you will get warning from the compiler since scanf takes the address of the element to be scanned and student.name points to the first character of the string name. So Edit the scanf arguments to be :

scanf("%s", student.name); 
.
scanf("%s", student.department); 
.
scanf("%s", student.school);  

Note: You can also use fgets instead of scanf to avoid buffer overflow but you have to consider that fgets includes the newline character, \n, within the string, so you have to replace the \n with \0. See tricks for how to replace the \n with \0

3- The last error is in comparing strings, you should use the strcmp function to compare between two strings, the function returns 0 if the two strings are typical. Also the string literals sholud be put inside double quotation marks "". So you should modify the last block to be :

if (!strcmp(student.department, "Chemical"))                        
{                                                                   
    printf("Name : %s \t",student.name);                            
                                                                    
    printf("\n%sUNG%s00%d", student.school, "CHE", student.roll_no);
}                                                                   

Answer 2

Try something like that:

typedef struct{
    char name[100];
    int roll_no;
    char department[100];
    char school[100];
} students;

int main() {
    students student;
    char input[100];
    //inputs
    printf("Enter Name : " );
    fgets(student.name, 50, stdin);
    printf("\nRoll Number : ");

    fgets(input, 50, stdin);
    sscanf(input,"%d", &student.roll_no);

    printf("\nDepartment : ");
    fgets(student.department, 50, stdin);
    printf("\nSchool : ");
    fgets(student.school, 50, stdin);

    if (strcmp(student.department, "Chemical") == 0)
    {
        printf("Name : %s \t",student.name);

        printf("\n%s %d", student.school, student.roll_no);
    }
    return 0;
}