How can I know that I have g++ installed in my ubuntu? [duplicate]

I have recently installed ubuntu 14.04 . I tried to run a c++ code by a command like this:

g++ first.cpp -o first

Then it said:

The program 'g++' is currently not installed. You can install it by typing:
sudo apt-get install g++

And then I did. After typing it and pressing enter it showed a message like this:

gedit is already the newest version.
libgrail6 is already the newest version.
xserver-xorg-core is already the newest version.
libgdata13 is already the newest version
...

(and many more lines like this)

Then I tried to run the same command given above again. But the terminal said again that I don't have g++ installed. What am I missing here? How to run the C++ code now?

Solution 1:

To find out what compilers are installed, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

dpkg --list | grep compiler

Solution 2:

Type "gcc" in terminal and then press Tab in your keyboard,the versions of gcc that are installed,will be shown. good luck