mbstring is missing for phpmyadmin in ubuntu 16.04

If you want to use php 5.6 instead of php 7

1.

Install php 5.6 mbstring package:

sudo apt-get install php5.6-mbstring

2.

sudo phpenmod mcrypt
sudo phpenmod mbstring

3.

Restart apache:

sudo service apache2 restart

 Done! 

source : https://askubuntu.com/questions/772397/mbstring-is-missing-for-phpmyadmin-in-ubuntu-16-04