Hide current working directory in Ubuntu Terminal

Just type below command in the Terminal.
export PS1='\u@\h:~$ '

Add above command to the bashrc file, so you do not have to type in the command again every time you load a new terminal.
sudo vi $HOME/.bashrc

Go to the bottom of the file and add the following using a editor such as VI.
export PS1='\u@\h:~$ '