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

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 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 keyword is used to define a function in PHP?

A). define

B). function

C). declare

D). method

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 declare a variable-length argument list in a function?

A). vararg

B). args

C). params

D). ...$args

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 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

What is the output of the following PHP code?

<?php
function multiply(...$args) {
$result = 1;
foreach ($args as $value) {
$result *= $value;
}
return $result;
}
echo multiply(2, 3, 4);
?>

A). 24

B). 9

C). 6

D). 2

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 will be the output of the following PHP code?

<?php
function uppercase($str) {
return strtoupper($str);
}
echo uppercase('hello');
?>

A). HELLO

B). hello

C). Uppercase

D). Undefined function: uppercase