Hi !

I recently shifted to linux OS and compilation of all my C programs on it has worked fine with the gcc compiler. I tried to compile my c++ programs on linux but it somehow gave me some errors which I cannot understand. I used the command
"g++ filename.cpp"

This is a simple program I tried to compile

Code:
#include<iostream>
int main()
{
        cout << " hello";
        return 0;
}
The error I get is :

eg325.cpp: In function `int main()':
eg325.cpp:4: `cout' undeclared (first use this function)
eg325.cpp:4: (Each undeclared identifier is reported only once for each
function it appears in.)
what am I doing worng,

also when i replace the iostream with iostream.h why do I get a huge warning ?

/usr/include/c++/3.2.2/backward/backward_warning.h:32:2: warning: #warning This
file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples
include substituting the <X> header for the <X.h> header for C++ includes, or <sstream> instead of the deprecated header <strstream.h>. To disable this warning
use -Wno-deprecated.