Install intl PHP extension for XAMPP and Magento OSX High Sierra

First —Check which php path is set i.e.

which php

If you are using xampp on your mac it should be:

/Applications/XAMPP/xamppfiles/bin/php

but if its

/usr/bin/php

you need to change your php path

PATH="/Applications/XAMPP/xamppfiles/bin:${PATH}"

Lets install with homebew

brew tap kyslik/homebrew-php
brew install kyslik/php/php70-intl

Change php.ini

nano /Applications/XAMPP/xamppfiles/etc/php.ini

Add this line:

extension=/usr/local/Cellar/php70-intl/[your-version]/intl.so