<?php
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array); // $key = 1;
?>
foreach($yourArray as $key => $value) {
echo '<a href="' . $value . '">' . $key . '</a>';
}
// OR
//Use functions
key($array); //Returns current key
reset($array); //Moves array pointer to first record
current($array); //Returns current value
next($array); //Moves array pointer to next record and returns its value
prev($array); //Moves array pointer to previous record and returns its value
end($array); //Moves array pointer to last record and returns its value