foo.cc: In function 'int main()':
foo.cc:12:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for(int i = 0; i < arr.length(); i++)
      |                    ~~^~~~~~~~~~~~~~
foo.cc:24:13: warning: 'ch' may be used uninitialized [-Wmaybe-uninitialized]
   24 |     cout << ch << endl;
      |             ^~
foo.cc:9:10: note: 'ch' was declared here
    9 |     char ch;
      |          ^~

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