- implode: documentation ( source)
<?php
$heap = new SplMinHeap;
$heap->insert([1, 1, 0]);
$heap->insert([2, 2, 1]);
$heap->insert([1, 2, 1]);
$heap->insert([2, 1, 3]);
$heap->insert([1,1,1]);
$heap->insert([1, 1, 3]);
foreach ($heap as $item) {
echo implode(' ', $item) . "\n";
}