Switch between multiple versions of GNU compilers

1sudo add-apt-repository ppa:ubuntu-toolchain-r/test
2sudo apt update

1sudo apt install gcc-11 gcc-12 gcc-13
2sudo apt install g++-11 g++-12 g++-13
3sudo apt install gfortran-11 gfortran-12 gfortran-13

 1sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 11
 2sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 12
 3sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 13
 4
 5sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-11 11
 6sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 12
 7sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-13 13
 8
 9sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-11 11
10sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-12 12
11sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-13 13

1sudo apt list gcc-11
2sudo apt install aptitude
3sudo aptitude install gcc-11=11.2.0-19ubuntu1