Add the PPA
sudo add-apt-repository ppa:ondrej/php
Update repos
sudo apt-get update
I got depencancy error while i was installing PHP 7.1, so i had to install the dependancies first.
Install the necessary packages
sudo apt-get install libapache2-mod-php7.1 php7.1-cli php7.1-common php7.1-json php7.1-opcache libssl1.0.2 php7.1-readline php-common php7.1-xml php7.1-mbstring php7.1-mysql php7.1-gd php7.1-curl
If "E: Package 'libssl1.0.2' has no installation candidate" error - change libssl1.0.2 to libssl1.0.0
Disable php5 modules present
sudo a2dismod php5
Enable php7.1 module
sudo a2enmod php7.1
Restart Apache
sudo service apache2 restart
Ref:- https://askubuntu.com/questions/760907/upgrade-to-16-04-php7-not-working-in-browser
PHP is not parsed in Virtual hosts present in user directories. This is because it is off by default for user directories.
Edit this file
sudo vim /etc/apache2/mods-available/php7.1.conf
and comment these lines
<IfModule mod_userdir.c>
<Directory /home/*/public_html>
php_admin_flag engine Off
</Directory>
</IfModule>
Restart apache
sudo service apache2 restart
-------- If the above doesn't help do this
PHP could be disabled for the virtual hosts. Try enabling it with "php_admin_flag engine on":
<VirtualHost *:80>
DocumentRoot "/Library/Server/Web/Data/Sites/Gradschool"
ServerName gradschool.local
<Directory /Library/Server/Web/Data/Sites/Gradschool>
php_admin_flag engine on
AllowOverride AuthConfig FileInfo
Order allow,deny
allow from all
</Directory>
</VirtualHost>
Ref : https://www.digitalocean.com/community/tutorials/how-to-upgrade-to-php-7-on-ubuntu-14-04
https://askubuntu.com/questions/967678/php-not-working-after-upgraded-to-ubuntu-17-10
libapache2-mod has been upgraded from libapache2-mod-php7.0 in Ubuntu 17.04 to libapache2-mod-php7.1 in Ubuntu 17.10 and Ubuntu 18.04. Open the terminal and type:
sudo apt-get install libapache2-mod-php7.1 # install PHP7 module for Apache2 webserver
sudo a2enmod php7.1 # enable the PHP7 module
sudo systemctl restart apache2.service # restart apache