What will be the output of the following PHP code?

function add($a, $b) {
return $a + $b;
}
$result = add(5, 3);
echo $result;
?>

Which PHP feature allows defining functions within other functions?

A). Nested functions

B). Inner functions

C). Enclosed functions

D). Internal 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 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

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'; }

What keyword is used to define a function in PHP?

A). define

B). function

C). declare

D). method

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

A). Dynamic functions

B). Global functions

C). Static functions

D). Callbacks

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
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!'; }

Which of the following statements is true about function names in PHP?

A). Function names are case-sensitive

B). Function names must start with a dollar sign ($)

C). Function names cannot contain numbers

D). Function names can contain spaces