implode array_merge

<?php
//implode.php
$arr = array('Hello','World!','I','love','Shanghai!');
echo implode(";",$arr);
echo '<hr>';
$arr = array('Hello');
echo implode(";",$arr);
/*
Hello;World!;I;love;Shanghai!
Hello
*/
?>

 

<?php
//array_merge.php
$a1=array("red","green");
$a2=array("blue","yellow");
print_r(array_merge($a1,$a2));
/*
Array ( [0] => red [1] => green [2] => blue [3] => yellow )
*/
?>