In PHP, to create an object from a class, you use the new keyword followed by the class name and parentheses. The correct option is "new." This instantiates an object based on the defined class. For more information, consult the PHP documentation on creating objects: http://php.net/manual/en/language.oop5.php

To start a session in PHP, you can use the session_start() function. This function must be called at the beginning of your PHP script before any session variables are accessed. It initializes a new session or resumes an existing session. For more details, refer to: http://php.net/manual/en/function.session-start.php

When using output control functions in PHP, you can handle errors by checking the return values of the functions. Many PHP functions return false or other specific values to indicate an error. By checking these return values, you can detect errors and take appropriate actions, such as displaying an error message, logging the error, or executing alternative code paths. Additionally, you can use conditional statements and error handling techniques like try-catch blocks to handle exceptions that may occur during function execution. It's important to handle errors effectively to ensure proper program execution and provide a good user experience.

To access a constant of a class in PHP, you can use the class name followed by the scope resolution operator :: and the constant name. For example: ClassName::CONSTANT_NAME This allows you to directly reference the value of a constant defined within a class without the need for object instantiation. The self keyword can also be used to access the constant within the class itself. To learn more, visit: http://php.net/manual/en/language.oop5.constants.php

To establish a connection to a MySQL database in PHP using the mysqli extension, you would use the mysqli_connect function. It takes four parameters: the host, username, password, and database name. These parameters are used to connect to the MySQL server and select the desired database. The function returns a connection object ($conn in this case) that can be used for further database operations. Ensure you provide the correct credentials and appropriate server details to establish a successful connection.

To troubleshoot an error when performing a network-related task using a PHP function, you can check the error message returned by the error_get_last() function. This function retrieves the last PHP error message. Reviewing this error message can provide insights into the issue that occurred during the function execution. Additionally, you can consider updating the PHP version and related extensions or reinstalling the PHP interpreter if the issue persists. By following these troubleshooting steps, you can identify and resolve the error encountered while performing a network-related task using a PHP function.

The correct option is 2. PHP superglobals, such as $_POST, $_GET, and $_SERVER, are accessible from any part of the script, including both within and outside functions. Superglobals are automatically available in all scopes and can be accessed from anywhere within your PHP script without the need for special considerations or modifications. They provide important information and resources that are needed across different parts of the script, making them globally accessible. It is important to note that superglobals can be accessed from both functions and other parts of the script. Learn more: https://www.php.net/manual/en/language.variables.superglobals.php

All of the given options can be done using either echo or print in PHP. Both echo and print can be used to output strings, variables, and HTML code. They can concatenate multiple strings together and display the result of an expression. The choice between echo and print depends on the specific requirements and personal preference. Learn more: https://www.php.net/manual/en/function.echo.php https://www.php.net/manual/en/function.print.php

The correct option is 2. The krsort() function in PHP sorts an associative array in descending order based on its keys, not in ascending order. It rearranges the elements of the array in such a way that the keys are sorted in descending order while maintaining the association between keys and values. The krsort() function directly modifies the original associative array. Sorting an associative array by keys in ascending order can be achieved using the ksort() function. Learn more: https://www.php.net/manual/en/function.krsort.php

The $_FILES superglobal array in PHP is used to access information about uploaded files. Some common uses of this array include accessing file information such as file name, file type, file size, and temporary file path. It is also used for validating file properties before processing, such as checking file size or file type. Additionally, it is used when moving uploaded files to desired directories. Properly handling and utilizing this array is crucial for effective file upload handling in PHP.