install qt4 ubuntu 20.04 code example

Example 1: install Qt5 ubuntu 20.04

sudo apt-get install build-essential
sudo apt-get install qtcreator
sudo apt-get install qt5-default

Example 2: install qt creator ubuntu 20.04

sudo apt install qtcreator

#Of course, that is the only way to install the IDE, but if we do not install the necessary libraries and compilers,
#it will not do us any good. So, install them.
sudo apt install build-essential

#f you have multiple versions of Qt, you probably want 5 to be the default QTCreator version to use.
#To do this, install the following package.
sudo apt install qt-5 defaut

#Then we can begin to develop. However, it is convenient to install the QT documentation and
#its examples to help the development.
sudo apt install qt5-doc qt5-doc-html qtbase5-doc-html qtbase5-examples