PHP files should be saved with a .php extension. The PHP interpreter processes files with this extension, executing any PHP code contained within and sending the resulting output (usually HTML) to the client's browser. Learn more: https://www.php.net/manual/en/tutorial.firstpage.php

In PHP, one of the ways to upload a file is by using an HTML form with the enctype attribute set to "multipart/form-data" and an input element of type "file". This allows the user to select a file to upload from their local system. This file will then be sent to the server for processing. The other options mentioned are not valid methods for file upload in PHP.

Accessing a class via :: represents static access, allowing you to access static properties or invoke static methods of a class. Learn more: http://php.net/manual/en/language.oop5.static.php

The setcookie() function in PHP takes the name of the cookie, its value, and its expiration time as arguments. These arguments allow you to define the properties of the cookie such as its name, value, and when it should expire. More information: http://php.net/manual/en/function.setcookie.php

To access the information stored in a cookie within a PHP script, you can use the $_COOKIE superglobal array. This array contains the names and values of the cookies sent by the client in the HTTP request. By accessing $_COOKIE['cookie_name'], you can retrieve the specific information stored in the cookie. See more at: http://php.net/manual/en/reserved.variables.cookies.php

To troubleshoot an error when sending an email using mail functions in PHP, you can check the error message returned by the error_get_last() function. This function retrieves the last PHP error message. By reviewing this error message, you can gain insights into the issue that occurred during the email sending process. Additionally, you can consider updating the PHP version and related extensions or reinstalling the mail server software if the issue persists. These troubleshooting steps can help identify and resolve errors encountered during the email sending operation in your PHP script.

The correct option is 1. A common use case for the $GLOBALS superglobal in PHP is accessing or manipulating global variables within functions or classes. When you need to access a global variable from within a function or class, you can use the $GLOBALS superglobal to retrieve its value or modify it directly. This allows you to work with global variables without having to use the global keyword within each function or class method. However, it is generally recommended to minimize the use of global variables and consider alternative approaches, such as passing variables as parameters or using object-oriented design principles, for better code organization and maintainability. Learn more: https://www.php.net/manual/en/reserved.variables.globals.php

If you try to use a foreach loop on a non-array variable in PHP, it will result in a "Fatal error." This error occurs because the foreach loop expects an array as its argument to iterate over. If you attempt to use a non-array variable, PHP will throw a fatal error and halt the script execution. It is important to ensure that the variable passed to the foreach loop is an array to avoid encountering this error. Learn more: https://www.php.net/manual/en/control-structures.foreach.php

Functions in PHP are commonly used for input validation, database management, file manipulation, and many other tasks. They allow for code reuse and modular organization, making the code more maintainable and readable. Functions can be created to perform specific tasks and then called whenever needed within the PHP script. Learn more: https://www.php.net/manual/en/functions.user-defined.php

To establish an FTP connection in PHP, you can use the ftp_connect() function. This function takes the FTP server hostname as the parameter and returns a connection resource. For example, $connection = ftp_connect($ftpServer); establishes an FTP connection to the specified server and stores the connection resource in the $connection variable. This resource is then used for subsequent FTP operations such as uploading files or retrieving directory listings. The ftp_connect() function is specifically designed for establishing FTP connections in PHP.