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

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 function is used to return a value from a function and terminate its execution?

A). return

B). exit

C). break

D). continue

What will be the output of the following PHP code?
<?php
$greet = function($name) {
return 'Hello, $name!';
};
echo $greet('John');
?

A). Hello, John!

B). Hello, $name!

C). function($name) { return 'Hello, $name!'; }

D). John

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

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

B). To specify the return type of the function

C). To declare a variable within the function

D). To terminate the function execution

What will be the output of the following PHP code?
<?php
function greet($name = 'Guest') {
return 'Hello, $name!';
}
echo greet('Alice');
?

A). Hello, Guest!

B). Hello, Alice!

C). Hello, $name!

D). Function call will result in an error

Which keyword is used to define default parameter values in PHP functions?

A). default

B). var

C). const

D). None of the above

What will be 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 about returning values from PHP functions is true?

A). PHP functions can return multiple values simultaneously

B). PHP functions cannot return values

C). PHP functions must always return a value

D). PHP functions can only return values of type string

What is 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 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