technical questions on php code example

Example 1: php internship interview questions

$a = '1';
$b = &$a;
$b = "2$b";
echo $a.", ".$b;

Example 2: php interview questions

$text = "I like programming";
print_r (explode(" ",$text));
$strarr = array('Pen','Pencil','Eraser');
echo implode(" ",$strarr);