Sorting Names in a Structure. How can I sort the names in this structure using bubble

[angeltandoc]

I cannot manage to get the code for sorting the names in alphabetical order. Please help...

#include<stdio.h>
#include<string.h>
 
typedef struct{
    char criminalName[10];
    char criminalCase[20];
    int age;
    char dateCaptured[10];
    int criminalID;
    }criminal;//structure declaration
 
void add();
void view();
void option(int n);
void exit();
int menu();
void sort();
/*function calls*/
 
main(){
    int num;
 
    do{
        num = menu();
        option(num);
    }while(num!=3);
    //loop in choosing an action to be performed by the user
}
 
int menu() {
    int choice;
 
    printf("\nGood day officer! What task would you like to do?\n[1] Add Record\n[2] View record\n[3] Exit\nchoice: ");
    scanf("%d", &choice);//Menu for choosing an action to be performed by the user
 
    return choice;
}
 
void option(int n){
    switch(n){
        case 1:        add();//adding records of the criminal
                break;
 
        case 2:     view();//viewing the records of the criminal
                break;
 
        case 3:        printf("Goodbye! Thank you for using this program.\n");//Goodbye Message
                break;
 
        default:     printf("Error! Choice Invalid!\n");//if the option entered is greater than 3
    }
}
 
 
int i, j;
char temp[7];
criminal crime[10];//variable declarations
 
void add(){
 
    for(i=0; i<10; i++){
 
        printf("Enter criminal's name: ");
        scanf("%s", crime[i].criminalName);
 
        printf("Enter criminal case: ");
        scanf("%s", crime[i].criminalCase);
 
        printf("Enter criminal age: ");
        scanf("%d", &(crime[i].age));
 
        printf("Enter the date the criminal was captured: ");
        scanf("%s", crime[i].dateCaptured);
 
        printf("Enter criminal ID: ");
        scanf("%d", &(crime[i].criminalID));
 
        printf("\n");
    }
}//data to be filled up by the user
 
void view(){
 
        for(i=0; i<10; i++){
        printf("Name: %s \nCase: %s \nAge: %d \nDate Captured: %s \nID: %d \n", crime[i].criminalName, crime[i].criminalCase, crime[i].age, crime[i].dateCaptured, crime[i].criminalID);
        /*printing the data entered by the user*/
 
        printf("\n");
 
    }
 
}//viewing the records of criminals
void sort(){
         for ( i = 0 ; i <= 3 ; i++ )
    {
        for ( j = 0 ; j <= 3 - i ; j++ )
        {
            if ( strcmp ( crime[j], crime[j + 1] ) > 0 )
            {
                strcpy ( temp, crime[j] ) ;
                strcpy ( crime[j], crime[j + 1] ) ;
                strcpy ( crime[j + 1], temp ) ;
            }
        }
    }
}          /* end of sort() */        
 
 
//end of program

[weaknessforcats]

The code has many errors that indicate you are coding before writing down your logic. The code is a long way from compiling.

In the sort function, you need to swap two crime variables. You cannot do this using strcpy. You will have to write a function to copy one crime variable to another since tou have to copy each member of the struct. Use this function in the sort to swap crime variables.

Likewise, strcmp compares two strings and not two crime variables. Again write a function that compares two crime variables using the addresses of the variables plus another argument that says what is being sorted. The criminalName? The criminalCase? Try have this function return the same values as strcmp since programmers are used to those values.

I suggest you write these two functions first and get them working before you write the sort function.

[donbock]

Actually, you don't need to write a copy function because Standard C allows you to use assignment to copy one structure variable to another. That is:

criminal v1;
criminal v2;
v1 = v2;

Notice that this simple form might not be appropriate if the structure contains pointers to other variables. In that case you would have to decide on a pointer-by-pointer basis whether it makes more sense to copy only the pointer value or to allocate a new instance of the thing being pointed at and copy it too. Anything more that simple assignment would indeed call for a copy function. Simple assignment is usually sufficient for sort-swapping even when the structure contains pointers. Fortunately, you don't have to worry about this issue because your structure does not contain pointers.

[donbock]

A frequent idiom for sort-comparison functions is:

int compare_elem(const void *elem1, const void *elem2);

The return value is

• negative if *elem1 < *elem2
• zero if *elem1 == *elem2
• positive if *elem1 > *elem2

You don't have to follow this idiom if you don't want to. The first change I would be tempted to make is to use "const criminal *" instead of "const void *".