Ubuntu 19.10 Date - 2020-03-02 (March 02, 2020) Apache2 - Already installed PHP 7.3 and 7.4 are the only versions currently being supported
Steps to install PHP (as per instructions on https://www.tecmint.com/install-different-php-versions-in-ubuntu/)
sudo apt install php - This installs PHP 7.3
sudo apt install software-properties-common - This was already there when I tried.
sudo add-apt-repository ppa:ondrej/php - Installs the popular repo for setting up multiple PHP versions
sudo apt install php7.3 and sudo apt install php7.4 - Installs PHP 7.3 and PHP 7.4
https://www.php.net/supported-versions.php
sudo update-alternatives --config php - Shows a list of available PHP versions to choose, and proceed from there on
https://stackoverflow.com/questions/42619312/switch-php-versions-on-commandline-ubuntu-16-04
Install mostly required PHP extensions for development:
apt install php-pear php7.3-curl php7.3-dev php7.3-gd php7.3-mbstring php7.3-zip php7.3-mysql php7.3-xml php7.3-fpm libapache2-mod-php7.3 php7.3-imagick php7.3-recode php7.3-tidy php7.3-xmlrpc php7.3-intl php7.3-redis php7.3-pgsql php7.3-xdebugFor PHP 7.4, just replace the version i.e.
apt install php-pear php7.4-curl php7.4-dev php7.4-gd php7.4-mbstring php7.4-zip php7.4-mysql php7.4-xml php7.4-fpm libapache2-mod-php7.4 php7.4-imagick php7.4-recode php7.4-tidy php7.4-xmlrpc php7.4-intl php7.4-redis php7.4-pgsql php7.4-xdebug