How to go back to parts of the program?

[Sharmz]

Hello, Im new to this forum. Currently I am beginning to learn C and I have started a little quiz program and need help with one aspect of it

#include<stdio.h>
main()
{
     int i;
     char str[]="You are correct!";
     char str2[]="You are incorrect, please start over";
     char str3[]="yes";
     char str4[]="no";
     char str5[5];
     
     printf("Welcome to the quiz\n");
     printf("There are 5 questions\nplease type yes or no to the questions\n");
     printf("If you get a question wrong, start over!\n");
     
     printf("I am a girl. yes or no?\n");//question 1
     gets(str5);
     i = 0;
     if (str5 == str4){
              printf"Please start over\n");

How can i make it so that the program goes back to printf("Welcome to the quiz\n"); when there is an incorrect answer

any other improvements on my code would be nice, im always happy to learn
Thanks!

[tabstop]

If you feel like being structured, you want to use a loop. You can use a goto, if you have the proper safety equipment.

Also, you should note that the condition "str5==str4" will always and forever be false. Two different arrays (which str4 and str5 are) can never compare equal. To compare the strings that str4 and str5 may be, you should use strcmp in the <string.h> header.

[Sharmz]

I fixed up the comparison of the strings but still am confused about the jumping. how is the goto used?

[tabstop]

If you search the board using "goto" as a keyword, you will find some examples of its use. Further than that I will not go.

[Adak]

The main() function calls the menu() function. The menu() function has a huge do-while loop in it, so everything branches out from the menu() according to the user's choice, and then it returns to the large do-while loop, back in menu.

int menu()   {
    char choice;  
   //etc.

   do   {

       system("cls");
       print your header here
       print a space or two
       print the body of your menu, here

       Get user's choice
       choice = tolower(choice);

       switch(choice)   {

         case 'a': handle_case_a(); output_from_a(); break;
         case 'b': handle_case_b(); break;
         //etc.

         default: print "Oops! I don't have a response for that choice. Please try again."

       }

   }while(choice != 'q');
   return 0;
}

Something along those lines should put you on the right track. *Please*, don't use "goto's", for crying out loud!

[Sharmz]

after the first post I resulted to goto but i know its a bad habit so I need to change it!! here is my program with goto

 next:
     do{
     printf("Magnum opus means great work. yes or no?\n");//question 1
     gets(str5);
     } while (strcmp (str3, str5) != 0);//correct answer is yes
     puts ("Correct answer!");
     
     printf("A paragon is a self contradictory statement. yes or no?\n");//question 2
     gets(str5);
     if (strcmp (str4, str5) != 0){ //correct answer is no 
                printf("%s\n", str2);
                c = getc(stdin);
                goto next;
                }
     else{
          printf("A dystopia is a perfect world. yes or no?\n");
          }
          gets(str5);
     if (strcmp (str4, str5) != 0){ //correct answer is no 
                 printf("%s\n", str2);
                  c = getc(stdin);
                goto next;
                }

[dwks]

Adak's post should let you figure out how to eliminate the goto.

Another hint:

do {
    /* ... */
} while(quit == 0);

@tabstop: probably not a good idea to mention goto to someone just learning C . . . .

[Adak]

Instead of the ugly line "goto next", why not use the more elegant "continue".

I have nothing against goto's - they are exactly what the assembly language is probably using. But we're not assembly compilers, and we don't want goto's in a program except in a very few circumstances, because they are SO EASY to abuse, and make the resulting program SO HARD to follow, when you have to modify/extend/or correct it.

True story:
When I was learning to program, the instructor related how he had been offered $50,000 if he would re-write a current program in use by the college. (This was when $50,000 was worth 3-5 X as much as it is, today - so a *lot* of money.)

You guessed it, it was an older program, that was riddled with goto's - goto's here, goto's there, goto's coming out your ears, nose, and well, you name it.

He declined, and so did every contractor who reviewed samples of the source code. The "noodle" effect of the goto's was just *unbelievable*. The program was eventually re-written from the ground up, because of it.

[Salem]

gotos and gets() - ugh.
Worse still, while you're still proud of it, you're beyond help.

[noops]

One improvement is to avoid cryptic names for your variables. str4, str3, are not very descriptive. Name them something humanreadable like 'yes_answer', 'no_answer'.