Which of the following is a correct way to destroy a specific session variable in PHP?
- unset($_SESSION['variable_name']);
- session_destroy();
- session_unset();
- session_unset($_SESSION['variable_name']);
The correct way to destroy a specific session variable in PHP is by using the unset function, followed by the variable name in $_SESSION. This clears the variable without destroying the entire session.
What does the PHP function func_num_args() return?
- The number of function arguments
- The function name
- An array of function arguments
- An associative array of arguments
The func_num_args() function returns the number of function arguments, which is useful for functions with a variable number of arguments.
In a database transaction, what does the term "atomicity" refer to?
- The transaction's ability to be rolled back if an error occurs
- The transaction's ability to be divided into smaller parts
- The transaction's ability to be completed without any errors
- The transaction's ability to be scheduled concurrently
"Atomicity" in the context of a database transaction refers to its ability to be completed without any errors. It ensures that all the operations within the transaction are executed successfully, or the transaction is rolled back entirely if any part of it fails, maintaining the database's integrity.
How do you call a user-defined function in PHP?
- call myFunction()
- myFunction()
- invokeFunction(myFunction)
- execute myFunction()
To call a user-defined function in PHP, you simply use the function name followed by parentheses. For example, 'myFunction()' would call the function 'myFunction'.
In dynamic forms where fields can be added or removed by the user, the server-side processing in PHP should use the ________ function to ensure data integrity.
- 'isset()'
- 'array_push()'
- 'count()'
- 'filter_var()'
The correct option is 'count().' In dynamic forms, where the number of fields can change, using 'count()' helps ensure data integrity by determining how many fields have been submitted and handling them appropriately. This is important for server-side validation.
Which function in PHP returns a formatted string?
- sprintf()
- printf()
- str_format()
- format_string()
The sprintf() function in PHP is used to return a formatted string. It allows you to create formatted strings using placeholders and values, similar to printf() in C.
Which PHP function can be used to customize the error handler?
- set_error_handler()
- custom_error_handler()
- modify_error_handler()
- handle_error()
The set_error_handler() function in PHP is used to customize the error handler. It allows you to define a custom error-handling function to manage how errors are handled in your PHP application.
In PHP, the superglobal that can be used to get variables passed to the current script via URL parameters is ________.
- $_GET
- $_REQUEST
- $_POST
- $_SESSION
The $_GET superglobal in PHP is used to retrieve variables passed to the current script via URL parameters. It's commonly used for reading data from URLs.
When a user logs out of a web application, which PHP function should be used to completely destroy a session?
- session_destroy()
- session_start()
- session_unset()
- unset($_SESSION)
The session_destroy() function is used to completely destroy a session in PHP, ensuring the user is logged out and their session data is wiped clean.
You are working on an online exam portal. To ensure that the user doesn't get the same session ID even if they retake the exam, what should you do at the beginning of each exam?
- Regenerate a New Session ID
- Use Local Storage for Session Management
- Maintain the Same Session ID
- Use Cookies for Session Management
To ensure that the user gets a new session ID for each exam attempt, it's crucial to "Regenerate a New Session ID" at the beginning of each exam. This prevents session re-use and maintains exam integrity.
You're developing a PHP application where you need to segregate classes that handle database operations and email sending. Which feature of PHP allows you to group these classes in a way that they can coexist even if they have the same class name?
- Namespaces
- Traits
- Interfaces
- Abstract Classes
Namespaces in PHP allow you to group classes and avoid naming conflicts, even if they have the same class name. This is essential for organizing code and preventing naming collisions.
Which function can be used in PHP to filter and sanitize user input?
- filter_input()
- sanitize_input()
- validate_input()
- clean_user_input()
The filter_input() function in PHP is used to filter and sanitize user input, ensuring it meets specific criteria or requirements. It's crucial for data security.