CODEWITHSUNDEEP
phpurlurl-parameters
user2389087
user2389087

Reputation: 1762

PHP check if url parameter exists

I have a URL which i pass parameters into

example/success.php?id=link1

I use php to grab it

$slide = ($_GET["id"]);

then an if statement to display content based on parameter

<?php  if($slide == 'link1') { ?>
   //content
 } ?>

Just need to know in PHP how to say, if the url param exists grab it and do the if function, if it doesn't exist do nothing.

Upvotes: 86

Views: 232830

Answers (6)

웃웃웃웃웃
웃웃웃웃웃

Reputation: 11984

Use isset().

if (isset($_GET["id"])) {
    // do something when a parameter exists
}

You can check the existence and equality in a single condition too

if (isset($_GET["id"]) && $_GET["id"] === 'link1') {
    // exists and equal to link1
}

However, it would be more convenient to define a variable first, using ?? shorthand, and then use it in a condition

$slide = $_GET["id"] ?? '';
...
if($slide === 'link1') {
    // equal to link1
}

Here, an empty string is used as a default value in case parameter is not defined. You can change it to any other value.

Upvotes: 138

hjelmeir
hjelmeir

Reputation: 106

I know this is an old question, but since php7.0 you can use the null coalescing operator (another resource).

It similar to the ternary operator, but will behave like isset on the lefthand operand instead of just using its boolean value.

$slide = $_GET["id"] ?? 'fallback';

So if $_GET["id"] is set, it returns the value. If not, it returns the fallback. I found this very helpful for $_POST, $_GET, or any passed parameters, etc

$slide = $_GET["id"] ?? '';

if (trim($slide) == 'link1') ...

Upvotes: 4

jimshot
jimshot

Reputation: 109

Why not just simplify it to if($_GET['id']). It will return true or false depending on status of the parameter's existence.

Upvotes: 0

Faruque Ahamed Mollick
Faruque Ahamed Mollick

Reputation: 792

Here is the PHP code to check if 'id' parameter exists in the URL or not:

if(isset($_GET['id']))
{
   $slide = $_GET['id'] // Getting parameter value inside PHP variable
}

I hope it will help you.

Upvotes: 10

rich
rich

Reputation: 1226

if(isset($_GET['id']))
{
    // Do something
}

You want something like that

Upvotes: 71

Your Common Sense
Your Common Sense

Reputation: 157828

It is not quite clear what function you are talking about and if you need 2 separate branches or one. Assuming one:

Change your first line to

$slide = '';
if (isset($_GET["id"]))
{
    $slide = $_GET["id"];
}

Upvotes: 4

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