How to redirect to another URL if query string match with a specific word

Issue

Am using the below code to redirect if the url string matches how ever the code is throwing "Warning: Use of undefined constant" error also the code does not work if the String is Case Sensitive, Please help me solve this issue (php version 7.2)

<?php 
if(isset($_GET['Keyword'])){
    if($_GET['Keyword'] == Test){
        header('Location: http://www.anotherURL.com');
        exit ();
    }
}
?>

Solution

actually your error says

Warning: Use of undefined constant

means Test used on line 3 in code mentioned is not defined

either define Test like this

<?php 
define("TEST", "key words to match", true); //here true is used for case-insensitive
if(isset($_GET['Keyword'])){
    if($_GET['Keyword'] == Test){
        header('Location: http://www.anotherURL.com');
        exit ();
    }
}
?>

or use it as a string

<?php 
if(isset($_GET['Keyword'])){
    if($_GET['Keyword'] == "Test"){ //qoutes " are necessary for string 
        header('Location: http://www.anotherURL.com');
        exit ();
    }
}
?>

Answered By - Ahmed Raza