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

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

A). To split a string into an array based on a specified delimiter.

B). To join array elements into a string using a specified delimiter.

C). To sort an array in ascending order.

D). To merge two or more arrays.

Which attribute of the HTML <form> element specifies the HTTP method to be used when submitting the form data?

A). method

B). action

C). type

D). enctype

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']

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 attribute of the HTML <form> element specifies the HTTP method to be used when submitting the form data?

A). method

B). action

C). type

D). enctype

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

A). redirect()

B). header()

C). forward()

D). location()

Which PHP function is used to handle file uploads?

A). upload_file()

B). process_upload()

C). handle_upload()

D). move_uploaded_file()

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

A). is_array()

B). check_array()

C). array_check()

D). isArray()

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

A). $_POST

B). $_GET

C). $_REQUEST

D). $_SERVER