What function is used to validate email addresses 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

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()

What is the purpose of the trim() function in PHP?

A). To remove whitespace from the beginning and end of a string.

B). To truncate a string to a specified length.

C). To convert a string to lowercase.

D). To convert a string to uppercase.

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

A). $_GET['username']

B). $_POST['username']

C). $_REQUEST['username']

D). $_SERVER['username']

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

A). $_POST

B). $_GET

C). $_REQUEST

D). $_SERVER

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

A). $_POST

B). $_GET

C). $_REQUEST

D). $_SERVER

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()

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()

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

A). redirect()

B). header()

C). forward()

D). location()

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'])