The extension is installed by default on PHP 5.3 and above. You can look for it by running the following command:
php -m | grep 'intl'
If the extension is not present, you can install it manually by following the installation guide. If you're using Ubuntu, you can directly run the following commands.
sudo apt-get update sudo apt-get install php5-intl
If you're using PHP7 on your machine, you need to add the (
ppa:ondrej/php) PPA, update your system and install ...