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

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

A). Dynamic functions

B). Global functions

C). Static functions

D). Callbacks

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 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

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 defining functions within other functions?

A). Nested functions

B). Inner functions

C). Enclosed functions

D). Internal functions

What is the purpose of the return statement in PHP functions?

A). To terminate the function execution

B). To output a value from the function and terminate its execution

C). To define the function name

D). To declare a variable within the function

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

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 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'; }