Thread: issue with switch statement

HI there,

I implemented a menu with a switch statement with which one can navigate through the different options I offered, which coincide, in turn, with the cases on the switch statement.

I intended the line that contains 'default' for the menu to return to the initial state, that is where it asks me for the options I want to enter.

However instead of returning to the default state in which I can select the option that I want, the program terminates. Everything else works fine in the program... I thought about implementing a goto statement but this would be in violation of 'good programming practices' .... what can I do?

Also in order for the program to continue until the end of the process I removed the break; statements within the switch statement. Is this orthodox? I am thinking that perhaps I should have used if statements and do whiles... any suggestions?

Thank you

Code:

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

    int option;

    menu();


  printf("Enter option: "); // this is the state in which I want the program when finishing <<<HERE
      scanf("%d",&option);

  switch (option) {

      case 1:printf("Create employee\n");
    fill_staff(); // takes index from user 
    employee_create(); // fills an array with index above

      case 2: printf("Enter employee data\n");
    for (d = 1; d <= emp_num; d++)
    employee_data(); //enter data for the employees created

    case 3:printf("Print employee list\n");
    for (d = 1; d <= emp_num; d++)
    print_employee(); //prints the array of employees
   
    default: printf("\n\n\nEnter option: "); //Return back to the original state and continue choosing options -- THIS IS WHERE THE PROBLEM IS <<<
      scanf("%d",&option);
  }
 
    return (EXIT_SUCCESS);
}

It's normally

Code:

case 1:
   // some stuff
   break;

I re-wrote the code to include the suggestion...However what I get now is that when I select an option it is permanently stuck in that option. If I select 'create employee' which corresponds to case 1 then it permanently asks me to enter employees. Did I do the while statement right? How do I move on to other cases? I post the updated code below

Code:

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

    int option;

    menu();


  printf("Enter option: ");
      scanf("%d",&option);


  while (option!=0){

  switch (option) {

      case 1:printf("Create employee\n");
    fill_staff(); // takes index from user
    employee_create(); break;// fills an array with index above

      case 2: printf("Enter employee data\n");
      for (d = 1; d <= emp_num; d++)
    employee_data(); break;//enter data for the employees created

    case 3:printf("Print employee list\n");
    for (d = 1; d <= emp_num; d++)
    print_employee();break; //prints the array of employees

     case 4:printf("Exit program: ");
            option = 0;break;

    default: printf("\n\n\nEnter option: "); //Return back to the original state and continue choosing options
      scanf("%d",&option);break;
        }

  }
 
    return (EXIT_SUCCESS);
}

default: printf("\n\n\nEnter option: "); //Return back to the original state and continue choosing options
scanf("%d",&option);break;

Remove this and get scanf out of switch, in the end of while block. Also, case 4 is not needed and will not actually work since you would assign option a value of 0 and then immediately overwrite it with a user's response.

Hi GL SAM,

I think I am understanding you wrong... By removing the default line out of the switch I get an error. '... main.c:118: error: 'default' label not within a switch statement...'

If this is what you meant? I paste the code which does not work and thereafter the one that does work...

Code:

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

    int option;

    menu();


    printf("Enter option: ");
    scanf("%d", &option);


    while (option != 0) {

        switch (option) {

            case 1:printf("Create employee\n");
                fill_staff(); // takes index from user
                employee_create(); break;// fills an array with index above

            case 2: printf("Enter employee data\n");
                for (d = 1; d <= emp_num; d++)
                    employee_data();break; //enter data for the employees created

            case 3:printf("Print employee list\n");
                for (d = 1; d <= emp_num; d++)
                    print_employee(); break;//prints the array of employees

            case 4:printf("Exit program: ");
                option = 0;break;


        }
        default: printf("\n\n\nEnter option: "); //Return back to the original state and continue choosing options <<< THIS IS MOVED OUT OF THE SWITCH STATEMENT
        scanf("%d", &option);break;
    }

    return (EXIT_SUCCESS);
}

If I, on the other side, remove the break; statements I get the desired result.... why is that? I paste the code that works below:

Code:

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

    int option;

    menu();


    printf("Enter option: ");
    scanf("%d", &option);


    while (option != 0) {

        switch (option) {

            case 1:printf("Create employee\n");
                fill_staff(); // takes index from user
                employee_create(); // fills an array with index above

            case 2: printf("Enter employee data\n");
                for (d = 1; d <= emp_num; d++)
                    employee_data(); //enter data for the employees created

            case 3:printf("Print employee list\n");
                for (d = 1; d <= emp_num; d++)
                    print_employee(); //prints the array of employees

            case 4:printf("Exit program: ");
                option = 0;

            default: printf("\n\n\nEnter option: "); //Return back to the original state and continue choosing options
                scanf("%d", &option);
        }

    }

    return (EXIT_SUCCESS);
}

You might want to consider something like this:

Code:

int option = menu();
while (option != OPTION_QUIT) {
    switch (option) {
        /* handle valid options */
    default:
        /* print error message concerning invalid option */
    }
    option = menu();
}

My idea is that handling the menu consists of two parts: printing it, and reading the menu option. Thus, menu() does both (possibly by calling other functions that handle the two individual parts), then returns the option read.

Now, instead of printing the menu in the default case, you print an error message. It is always the case that as long as the option is not an option to quit (i.e., the option matches the OPTION_QUIT constant), the menu will be printed and the next option read.