infintite loop

I have a pice of code

Code:

---

        do
        {
                clrscr();
                printf("\n\n\t\t <<< MAIN MENU >>>");
                printf("\n\n\t 1. Insert ");
                printf("\n\n\t 2. Delete ");
                printf("\n\n\t 0. Exit ");
                printf("\n\n\t\t Enter your choice  :  ");
                scanf("%d",&ch);
                switch(ch)
                {
                        case 1 : printf("\n Enter data to be inserted : ");
                                scanf("%d",&data);
                                enqueue(&qarr,data);
                                printf("\n\nThe queue is :-\n\n");
                                display(qarr);
                                break;

                        case 2 : printf("\n\nBefore Deletion queue is :-\n\n");
                                display(qarr);
                                dequeue(&qarr);
                                printf("\n\nThe new queue is :-\n\n");
                                display(qarr);
                                break;

                        case 0 :exit(0);

                        default: printf("\n Invalid Choice, try Again !!!");
                }
                printf("\n\n\n\n\t\t Press any key to continue...");
                getch();
        }
        while(1);

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if during runtime i input a character into choice instead of an integer the progam goes into infinite loop.

I know how to rectify the problem. Bt i don't know why the reason due to which the program is going into an infinite loop. Please help

Code:

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char c;

while ((c = getchar()) != EOF && c != '\n');

---

This should consume any characters that were not assigned to variables by scanf().

NB!
You can get some funky behavior if there are no characters to consume.

Thanks, but can you please tll me why is the program going into an infinite loop in the first place?

Ah. Sure. Because you never do anything to break out of the do-while loop, except in case 0 where you exit the program. There's still input in the buffer that scanf() can't assign to ch so you get the default case again and do-while loop runs again. Ad nauseam.

Code:

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int c;

while ((c = getchar()) != EOF && c != '\n');

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Question 12.1

Thanks. I keep missing that.