<?php
echo gettype($var) . ' - |' . $var . '| - ';
$var;
echo gettype($var) . ' - |' . $var . '| - ';
$var = '';
echo gettype($var) . ' - |' . $var . '| - ';
$var = 'teste';
echo gettype($var) . ' - |' . $var . '| - ';

//https://pt.stackoverflow.com/q/247899/101