Answers for "ubuntu 14.04 lts update PHP Version 5.5.9-1ubuntu4.14 to PHP 7.3+"

ubuntu 16 upgrade php 7.0 to 7.4

sudo apt install -y php7.4-mysql php7.4-dom php7.4-simplexml php7.4-ssh2 php7.4-xml php7.4-xmlreader php7.4-curl  php7.4-exif  php7.4-ftp php7.4-gd  php7.4-iconv php7.4-imagick php7.4-json  php7.4-mbstring php7.4-posix php7.4-sockets php7.4-tokenizer

ubuntu 16 upgrade php 7.0 to 7.4

sudo apt install -y php7.4 php7.4-cli php7.4-common php7.4-fpm