PHP Install on Mac

I use CakePHP 2 and 3 so they need intl and mcrypt

brew install php71 --with-httpd24
brew install php71-imagick
brew install php71-intl
brew install php71-mcrypt

Also I found that calling a function as follows fails

# this PHP 5.x code calls a function name stored in $recieved['operation'] 
# called create_pdf
# However this fails in PHP 7.1
$result = $this->$received['operation']($received);

# the solution is to first
# assign the function name to a variable 
$func = $received['operation'];

# and then it will work successfully when called
$result = $this->$func($received);