error: `cout’ was not declared in this scope

Error compiling C++ using GCC under Linux:

#include< iostream>
int main()
{
cout < < “Hello World!” < < endl;
return 0;
}

compiler error:
$g++ s.> s.bbpp: In function ‘int main(int, char**)’:
The



s.cpp:12: error: `cout’ was not declared in this scope

s.cpp:12: error: `endl’ was not declared in this scope

The reason:

C++ 1998 requires cout and endl to be called using ‘STD ::cout’ and’ STD ::endl’ formats, or using namespace STD;

Revised:

#include< iostream>

int main()

{
std::cout < < “Hello World!” < < std::endl;
return 0;
}

or

#include< iostream>

using namespace std;

int main(int argc, char *argv[])

{

cout < < “hello world” < < endl;
return 0;
}

Compile through.