Usage

Approach

Checking File Type Determine acceptable file extensions or MIME types. Use pathinfo( ) function to extract the file extension. Compare the file extension or MIME type against the list of allowed types. Checking File Size Determine the maximum allowed file size. Use $_FILES superglobal array to access the uploaded file’s size. Compare the file size against the maximum allowed size....

Syntax:

// Define allowed file types and maximum file size$allowedTypes = array('jpg', 'jpeg', 'png', 'gif');$maxFileSize = 2 * 1024 * 1024; // 2MB// Get file details$fileName = $_FILES['file']['name'];$fileSize = $_FILES['file']['size'];$fileType = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));// Check file typeif (!in_array($fileType, $allowedTypes)) { echo "Only JPG, JPEG, PNG, and GIF files are allowed.";}// Check file sizeif ($fileSize > $maxFileSize) { echo "File size exceeds the maximum limit of 2MB.";}// If both checks pass, proceed with file upload...

Difference between File Type and Size

Checking File Type Checking File Size Verify file extensions or MIME types against a predefined list Compare the file size against the maximum allowed size Use functions like pathinfo() or MIME type detection to determine file type Access file size information using $_FILES superglobal array Prevents uploading of disallowed file types Prevents uploading of excessively large files...

Usage

Security: File type and size validation help prevent security vulnerabilities such as file upload attacks or denial of service attacks. User Experience: Proper validation provides feedback to users about allowed file types and sizes, improving the user experience....