Dash in front of large letters PHP regular expressions

You can do the following:

 <?php echo preg_replace_callback( '/(?<!^)([AZ])/', function($match) { return '-'.strtolower($match[1]); }, 'masterAtHome'); 

This is a typical task of converting Camel Case strings to Snake Case (with minuses instead of underscores).

Here is one of the easiest conversion options:

 echo strtolower(preg_replace("/(?!^)([AZ])/", '-$1', 'masterAtHome')); 

In the example above, a group of characters (?!^) used to ignore a capital letter if it goes first in the line.

A working example on Ideone .