JuniorTheoryCommon

What does the program print?

PHP

<?php

$csv = 'red,green,,blue';
$parts = explode(',', $csv);
echo count($parts), ' ', implode('|', array_slice($parts, 1, 2)), "\n";

4 green|

Expecting explode to skip the empty piece between two commas: it returns every piece, the empty string included, so 'red,green,,blue' gives four parts.
Reading the third argument of array_slice as an end position: it is the number of elements, so array_slice($parts, 1, 2) takes the parts at positions 1 and 2.

JuniorTheoryCommon

PHP

<?php

$csv = 'red,green,,blue';
$parts = explode(',', $csv);
echo count($parts), ' ', implode('|', array_slice($parts, 1, 2)), "\n";

4 green|

Expecting explode to skip the empty piece between two commas: it returns every piece, the empty string included, so 'red,green,,blue' gives four parts.
Reading the third argument of array_slice as an end position: it is the number of elements, so array_slice($parts, 1, 2) takes the parts at positions 1 and 2.