What keyword is used to define a function in PHP?

What will be the output of the following PHP code?

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

A). 8

B). add(5, 3)

C). function add($a, $b) {
return $a + $b;
}

D). $a + $b

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

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 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 passing functions as arguments in PHP?

A). It allows functions to be called multiple times

B). It simplifies the function definition process

C). It enables dynamic function invocation and behavior

D). It prevents code duplication

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

A). vararg

B). args

C). params

D). ...$args

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