- var_dump: documentation ( source)
- array_merge: documentation ( source)
- in_array: documentation ( source)
<?php
$a = array("a" =>"b", "c"=>"d");
if(isset($a['a']))
echo "hi";
else
echo "hello";
$b = array("a","b","c");
if(in_array('a',$b))
echo "hi";
else
echo "hello";
var_dump(array_merge(array("1","2"), array("2","3","4")));