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ubuntu update php 7.4 to 8

sudo apt-get purge php7.*
# recommended 
sudo apt-get autoclean
sudo apt-get autoremove
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
# end recommended 
sudo apt-get install php8.0

upgrade php 8 ubuntu 20.04

# php -v (default PHP version)

# From PHP 8.0 to PHP 7.4:
sudo a2dismod php8.0
sudo a2enmod php7.4
sudo update-alternatives --set php /usr/bin/php7.4
sudo service apache2 restart

# From PHP 7.4 to PHP 8.0:
sudo a2dismod php7.4
sudo a2enmod php8.0
sudo update-alternatives --set php /usr/bin/php8.0
sudo service apache2 restart

php 7 to php 8 in ubuntu 20.04

sudo apt install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update
sudo apt install php8.0
 #install common extension 
sudo apt install php8.0-common php8.0-mysql php8.0-xml php8.0-xmlrpc php8.0-curl php8.0-gd php8.0-imagick php8.0-cli php8.0-dev php8.0-imap php8.0-mbstring php8.0-opcache php8.0-soap php8.0-zip php8.0-intl -y
  sudo a2dismod php7.0
  sudo a2dismod php7.1
  sudo a2dismod php7.2
  sudo a2dismod php7.3
  sudo a2dismod php7.4
sudo a2enmod php8.0
sudo service apache2 restart

installing php version 8 in Ubuntu 20+

#Rn the command as sudo
			• apt install software-properties-common
            • apt update
            • apt install php8.0