<?php
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
echo "Using array_search() function: <br>";
$key = array_search('green', $array); // $key = 2;
echo "Value green is at the location : ". $key."<br>";
echo "------------------------------------<br>";
echo "Using in_array() function: <br>";
$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
    echo "Got Irix";
}
if (in_array("mac", $os)) {
    echo "Got mac";
}

?>