What he said,
either put usingnamespace std;
after your header #include <iostream>
or put a using std::cout; ,
or put a std before your cout like std::cout<<"HELLO WORLD"<<std::endl;
you will discover that your program needs a pause to display the output,
either put a cin.get() before your return 0; or add this
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// For This Method You need to #include <limits>
cout<<"Push Enter To Quit"<<endl;
cin.sync();
cin.ignore(numeric_limits<streamsize>::max(),'\n');
return 0;