How can you access the value of a form field named "username" submitted via the POST method in PHP?

What is the purpose of the isset() function in PHP when handling form submissions?

A). To check if a variable is empty

B). To check if a variable is set and is not NULL

C). To check if a variable is numeric

D). To convert a variable to a string

How can you check if a checkbox is checked in PHP when submitted via a form?

A). isset($_POST['checkbox'])

B). $_POST['checkbox'] == 'checked'

C). $_POST['checkbox'] === 'checked'

D). empty($_POST['checkbox'])

Which PHP superglobal array is used to retrieve form data sent with the POST method?

A). $_POST

B). $_GET

C). $_REQUEST

D). $_SERVER

What function is used to check if a file upload operation was successful in PHP?

A). file_exists()

B). is_uploaded_file()

C). move_uploaded_file()

D). file_upload_successful()

What type of attribute is used in an HTML form to specify where to send the form data?

A). method

B). action

C). type

D). name

Which PHP function is used to sanitize user input to prevent SQL injection attacks?

A). strip_tags()

B). htmlspecialchars()

C). mysql_real_escape_string()

D). trim()

Which PHP function is used to redirect the user to another page?

A). redirect()

B). header()

C). forward()

D). location()

What type of attribute is used in an HTML form to specify where to send the form data?

A). method

B). action

C). type

D). name

Which function is used to check if a variable is an array in PHP?

A). is_array()

B). check_array()

C). array_check()

D). isArray()

How can you prevent SQL injection attacks in PHP?

A). Use prepared statements with parameterized queries.

B). Escape user input using the htmlspecialchars() function.

C). Sanitize user input using the filter_var() function.

D). Validate user input using regular expressions.