This is the guide of checking array contains specific word http://extracatchy.net/check-if-array-contains-a-specific-word-in-php/

array_string_check.php

<?php 

$students = array("Rahul, Salim, Aftab, Shahnawaz, Faizal, Sameer");
$stringtocheck = "Aftab";
if(is_our_student($students, $stringtocheck)) {
    echo "It is our student.";
} else {
    echo "Uknown child and he/she is not our student.";
}