/in/foo.cc: In function 'int main()':
/in/foo.cc:7:9: warning: 'ch' is used uninitialized [-Wuninitialized]
    7 |         if(ch=='J')
      |         ^~
/in/foo.cc:6:14: note: 'ch' was declared here
    6 |         char ch;
      |              ^~