Comparing URL strings in PHP - php

Question

I'm trying to use the query from a GET url to determine the content of a page.
This is what I have (sentences edited for clarity):
<?php
//decalre variables
$title ='';
$welcome = '';
$params = '';
$params = $_SERVER['QUERY_STRING'];
echo $_SERVER['QUERY_STRING'];
echo $params;
if ($params='') {
header('start.html') ;
} else {
if ($params === "selection=republic") {
//echo $params;
//echo 'Republic';
$title = "Private";
$welcome = "Our .";
$signoff = "The Republic will strike back!";
}
else if ($params === "selection=rebels") {
//echo $params;
//echo 'Rebels';
$title = "Comrade";
$welcome = "Hey comrade, welcome to the Underground Network!";
$declaration="You see,o's!";
$signoff = "Rebel!!";
}
else if ($params === "selection=robots"){
//echo $params;
//echo 'Robots';
$title = "Bit";
$welcome = "Our data ";
$declaration="Knowledge w.";
$signoff = "ed now.";
}
else {
echo 'There was an error - please go back.';
}
}
The first echo shows the correct URL, but the comparison gets stuck at the third option.
Help!

Answer 1

This comes from the triple = sign, that compares the value and the type. You should see the difference here.
I suggest you only use two equals and by the way, you could ease your code by using the $_GET['selection'] variable instead:
<?php
//decalre variables
$title ='';
$welcome = '';
$params = '';
$params = $_SERVER['QUERY_STRING'];
echo $_SERVER['QUERY_STRING'];
echo $params;
if (!isset($_GET['selection']) { // Check whether selection is set
header('start.html') ;
} else {
if ($_GET['selection'] == "republic") {
//echo $params;
//echo 'Republic';
$title = "Private";
$welcome = "Our .";
$signoff = "The Republic will strike back!";
}
else if ($_GET['selection'] == "rebels") {
//echo $params;
//echo 'Rebels';
$title = "Comrade";
$welcome = "Hey comrade, welcome to the Underground Network!";
$declaration="You see,o's!";
$signoff = "Rebel!!";
}
else if ($_GET['selection'] == "robots"){
//echo $params;
//echo 'Robots';
$title = "Bit";
$welcome = "Our data ";
$declaration="Knowledge w.";
$signoff = "ed now.";
}
else {
echo 'There was an error - please go back.';
}
}

Answer 2

There are way better ways of parsing the query string than $SERVER['QUERY_STRING'], specifically you can use $_GET to access a specific parameter. Example: www.example.com?name=Dave&age=30...
to get the name, you can do $_GET['name'] and it will return Dave. I think a better way to do this would be something like:
$selection = $_GET['selection'];
if (empty($selection)) {
header('start.html') ;
}
else {
$vars = array(
'republic'=>array('title'=>'Private', 'welcome'=> 'Our .', 'declaration'=>'', 'signoff' => 'The Replublic will strike back'),
'rebels'=>array('title'=>'Comrade', 'welcome' => "Hey comrade, welcome to the Underground Network!", 'declaration'=>"You see,o's!",'signoff' => "Rebel!!"),
'robots'=>array('title'=>'Bit', 'welcome'=>'Our data', 'declaration'=>'Knowlegge W', 'signoff'=>'Ed now')
);
list($title, $welcome, $declaration, $signoff) = $vars[$selection];
}