PHP check if url parameter exists

To check if a URL parameter exists in PHP, you can use the isset function. This function returns a boolean value indicating whether a variable with the specified name has been set and is not NULL.

For example, if you want to check if a URL parameter called id exists, you can use the following code:

<?php

if (isset($_GET['id'])) {
  // URL parameter exists
  echo 'URL parameter exists';
} else {
  // URL parameter does not exist
  echo 'URL parameter does not exist';
}

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You can also use the array_key_exists function to check if a key exists in an array. This function can be used to check if a URL parameter exists in the $_GET array:

<?php

if (array_key_exists('id', $_GET)) {
  // URL parameter exists
  echo 'URL parameter exists';
} else {
  // URL parameter does not exist
  echo 'URL parameter does not exist';
}