- implode: documentation ( source)
<?php
$value = 37;
$classes = [];
switch (true)
{
case ($value >= 100):
$classes[] = 'full';
case ($value > 0):
$classes[] = 'used';
case ($value == 0):
$classes[] = 'empty';
case false:
$classes[] = 'false';
}
echo 'class="' . implode(' ', $classes) . '"';