I have just installed gcc 4.7 from ppa repository. Ubuntu 12.04 already comes with 4.6. When I use command:
gcc --version
It tells me it is 4.6.3 to be exact.
I have no idea of how to launch the 4.7 compiler. In fact, I wouldn't mind erasing the former version and stay with 4.7 only (I guess that wouldn't be a problem).
How can I fix this?

gccfirstsudo apt-get remove gcc*then install the newer version – blade19899 Sep 27 '12 at 10:10