PHP file extension checker: Display messages for different file types

Last update on April 16 2025 12:57:25 (UTC/GMT +8 hours)

12. Check File Extension and Display Messages

Write a PHP script to check the file extension and display appropriate messages for different file types.

Sample Solution:

PHP Code :

<?php
  $filename = "i:/test.txt";
//$filename = "i:/CTips.pdf";
$fileExtension = pathinfo($filename, PATHINFO_EXTENSION);

switch ($fileExtension) {
    case "txt":
        echo "Text file detected.";
        break;
    case "jpg":
    case "jpeg":
    case "png":
        echo "Image file detected.";
        break;
    case "pdf":
        echo "PDF file detected.";
        break;
    default:
        echo "File type not supported.";
        break;
}
?>

Sample Output:

Text file detected.

PDF file detected.

Explanation:

In the above exercise -

The $filename variable holds the name of the file we want to check the extension for.
We use the pathinfo() function with the PATHINFO_EXTENSION constant to extract the file extension from the filename and store it in the $fileExtension variable.
We then use a switch statement to check the value of $fileExtension and perform different actions based on the detected file type.

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to examine a file's extension and display custom messages for image, text, and PDF files.
Write a PHP function to determine if a file extension belongs to a set of allowed types and output an appropriate message.
Write a PHP program to validate file extensions before processing file uploads and display error messages for disallowed types.
Write a PHP script to automatically rename files based on their extensions and output corresponding status messages.

PHP Code Editor:

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