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

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 feature allows defining functions without specifying their names?

A). Anonymous functions

B). Dynamic functions

C). Global functions

D). Static functions

What keyword is used to define a function in PHP?

A). define

B). function

C). declare

D). method

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 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

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

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

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

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