ubuntu 18.04 install clang 11

It is really to get clang installeed without cimpiling the source code.
1 gedit /etc/apt/sources.list

deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main
deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main

sudo apt-get update
sudo apt-get upgrade
wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
3
apt-get install clang-11 lldb-11 lld-11
apt-get install libc++-11-dev libc++abi-11-dev
4
cd /usr/bin
sudo ln -s clang-11 clang
sudo ln -s clang++-11 clang++
sudo ln -s /usr/bin/llvm-ar-11 /usr/bin/llvm-ar
sudo ln -s /usr/bin/llvm-as-11 /usr/bin/llvm-as
sudo ln -s /usr/bin/clangd-11 /usr/bin/clangd
sudo ln -s /usr/bin/clang-tidy-11 /usr/bin/clang-tidy

[1] https://apt.llvm.org/
[2] https://linuxhint.com/install-llvm-ubuntu/
[3] https://dwijaybane.wordpress.com/2018/07/20/llvm-clang-8-with-compiler-explorer/