How can I easily switch between PHP versions on Mac OSX?

Question

I would like to test my application on PHP 5.3 up to PHP 7.0.

Where and how can I install the versions and how can I switch them by running a small script?

Answer 1

Example: Let us switch from php 7.4 to 7.3

brew unlink php@7.4
brew install php@7.3
brew link php@7.3

If you get Warning: php@7.3 is keg-only and must be linked with --force Then try with:

brew link php@7.3 --force