What will be the output of the following PHP code?

$greet = function($name) {
return "Hello, $name!";
};
echo $greet("John");
?>

Which PHP feature allows defining functions within other functions?

A). Nested functions

B). Inner functions

C). Enclosed functions

D). Internal functions

Which PHP feature allows defining functions without specifying their names?

A). Anonymous functions

B). Dynamic functions

C). Global functions

D). Static functions

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 significance of default parameter values in PHP functions?

A). Default parameter values are required for all parameters in a function

B). Default parameter values allow specifying multiple default values for a parameter

C). Default parameter values allow parameters to be optional

D). Default parameter values allow specifying the data type of parameters

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()

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

A). vararg

B). args

C). params

D). ...$args

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 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

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 purpose of parameters in PHP functions?

A). To store values within the function

B). To define the return type of the function

C). To specify values that are passed to the function when it is called

D). To specify the visibility of the function