Given a character , convert it to upper or lower

Question

I don't know what is the error. Can somebody help me?
https://code.sololearn.com/c4mWVY3m37gq/?ref=app

Answer 1

Hi Geek
To take input, you have to use ampersand with variable -

scanf("%c",&ch);

Answer 2

What happens when you don't use ampersand?