What is the output of the following PHP code?

function multiply(...$args) {
$result = 1;
foreach ($args as $value) {
$result *= $value;
}
return $result;
}
echo multiply(2, 3, 4);
?>

Which PHP keyword is used to check if a function exists before calling it?

A). check_function()

B). function_exists()

C). function_check()

D). exists_function()

How do you define parameters in a PHP function?

A). Parameters are defined within parentheses after the function name

B). Parameters are defined using the keyword 'param'

C). Parameters are defined using curly braces {}

D). Parameters are defined using square brackets []

What is the output of the following PHP code?

<?php
$num = 10;
function testScope() {
global $num;
echo $num;
}
testScope();
?>

A). 10

B). 0

C). Undefined variable: num

D). Variable $num cannot be accessed outside the function

Which PHP keyword is used to declare a variable-length argument list in a function?

A). vararg

B). args

C). params

D). ...$args

Which of the following statements about return types in PHP functions is true?

A). PHP functions must always have a return type

B). PHP functions can have a return type specified using the 'returns' keyword

C). PHP functions can have a return type specified using the 'return' keyword

D). PHP functions can have a return type declared using type declarations

What is the output of the following PHP code?

<?php
function greet() {
echo 'Hello, World!';
}
if (function_exists('greet')) {
greet();
} else {
echo 'Function does not exist';
}
?>

A). Hello, World!

B). Function does not exist

C). Undefined function: greet

D). Function greet() { echo 'Hello, World!'; }

What will be the output of the following PHP code?

<?php
function outer() {
function inner() {
echo 'Inner function';
}
}
inner();
?>

A). Inner function

B). Function does not exist: inner

C). Undefined function: inner

D). Function inner() { echo 'Inner function'; }

Which of the following statements about variable scope in PHP functions is true?

A). Variables defined inside a function have global scope

B). Variables defined outside a function have local scope

C). Variables defined inside a function have local scope

D). Variables defined outside a function have global scope

Which PHP feature allows passing a function as an argument to another function?

A). Dynamic functions

B). Global functions

C). Static functions

D). Callbacks

Which PHP feature allows defining functions within other functions?

A). Nested functions

B). Inner functions

C). Enclosed functions

D). Internal functions