- array_map: documentation ( source)
- var_dump: documentation ( source)
- array_slice: documentation ( source)
- implode: documentation ( source)
- explode: documentation ( source)
<?php
$throwableName = 'Hello\World\Class\ClassName';
$classNameArr = explode('\\', $throwableName);
$className = implode('\\', array_map(function($item){ return $item[0]; }, array_slice($classNameArr, 0, -1))).'\\'.$classNameArr[count($classNameArr) - 1];
var_dump($className);