Can anybody help me out with the right input way?

Question

I have inputted like this
1
7
Y
1
8
Y
3
n,
it gives output as 0807 instead of 87 just ,
https://code.sololearn.com/c8DO6ClGWviV/?ref=app

Answer 1

Abhay
You're welcome. And about the reason for the space:

When we enter a menu choice we type a number followed by {Enter} key, also when we type a number to insert a new value into the stack - we type the number and hit {Enter} key.

It is the character of that {Enter} key that was left in the input buffer. scanf uses that leftover character when it sees that an input is needed for <option> variable.

If we put space before the %c - that leftover character will be ignored (because a space is not a format specifier), and the letter we type ('y' or 'n') will be stored correctly in <option> variable.

To confirm this you can test the scanf call for <option> variable like this:

scanf("%c", &option);
// no space before %c
printf("%d", option);
// output 10, the ASCII code for {Enter} key

I hope this shades a light even just a bit : )

Answer 2

I think you have written the input in a correct sequence, the problem is in the code. Make a few correction and I guess it'll work well.

● In the switch statement:
case 4:
break; instead of exit(0);

* There's no need to force exit when we can simply exit the menu loop.

● When asking confirmation:
scanf(" %c", &option);

* Notice the space before the %c specifier, it was necessary because the input stream buffer has a leftover byte from previous input. The leftover byte will be consumed in by the space.

● In the display function:
* Do check whether there is any data (top != -1) before going through the loop printing the data.

Try to make this changes and let me know how it goes.

Answer 3

Ipang ,wow the only thing missing was space before that %c ,which I would have never ever able to correct ,thks a lot and I still dunno why that space is really needed ,I have never given a space before % c lol , maybe it's due to the compiler ? or it will give 0 everywhere?