MCQs on Functions | PHP Basics
PHP functions are a core aspect of the language, enabling code reusability and modularity. In this guide, we dive deep into defining functions, handling parameters, understanding variable scopes, recursion, and leveraging built-in PHP functions to optimize your web development skills. Here are 30 multiple-choice questions (MCQs) covering each of these topics.
PHP Functions – MCQs
1. Defining Functions
- Which keyword is used to define a function in PHP?
- a) define
- b) function
- c) func
- d) method
- What is the correct way to call a user-defined function in PHP?
- a) call functionName();
- b) function functionName();
- c) functionName();
- d) exec functionName();
- Which of the following is a valid PHP function name?
- a) 2function
- b) my-function
- c) _function
- d) function name
- Can a function in PHP return multiple values directly?
- a) Yes
- b) No
- c) Only with arrays
- d) Only with objects
- What is the default return value of a PHP function if no return statement is provided?
- a) 0
- b) null
- c) false
- d) undefined
- How do you pass arguments by reference in PHP?
- a) Using &
- b) Using *
- c) Using @
- d) Using %
2. Function Parameters and Return Values
- What will happen if a function is called with fewer arguments than it is defined to accept?
- a) Error
- b) Warning
- c) Ignored
- d) None of the above
- What is the correct syntax for defining default parameter values in PHP?
- a) function myFunction($param=2)
- b) function myFunction($param: 2)
- c) function myFunction($param -> 2)
- d) function myFunction($param = 2)
- Can you specify the data type of a function parameter in PHP?
- a) Yes, using type hinting
- b) No, PHP does not support it
- c) Only in PHP 8+
- d) Only for objects and arrays
- Which of the following is a valid return type declaration in PHP 7+?
- a) function myFunction(): int
- b) function myFunction() -> int
- c) function myFunction() => int
- d) function myFunction() == int
- What is the output of the following code?
function test($a, $b = 2) { return $a * $b; } echo test(4);- a) 4
- b) 6
- c) 8
- d) Error
- How can you return multiple values from a PHP function?
- a) Using arrays
- b) Using objects
- c) Using references
- d) All of the above
3. Variable Scope (Global vs Local)
- What is the scope of a variable defined inside a function?
- a) Global
- b) Local
- c) Static
- d) Public
- How can you access a global variable inside a function?
- a) By using global keyword
- b) By using $GLOBALS array
- c) By passing it as a parameter
- d) All of the above
- What does the
statickeyword do in a function?- a) Makes variable global
- b) Preserves the value of a variable between function calls
- c) Makes variable accessible in all files
- d) Deletes the variable after use
- What will the following code output?
$x = 10; function demo() { global $x; $x = $x + 5; } demo(); echo $x;- a) 10
- b) 15
- c) 5
- d) Error
- Can a function have both global and local variables with the same name?
- a) Yes, but only one is accessible
- b) Yes, and both are accessible
- c) No, PHP will throw an error
- d) Only if defined with
static
- What is the use of
$GLOBALSarray?- a) It stores all local variables
- b) It stores all global variables
- c) It stores all static variables
- d) It stores all session variables
4. Recursion in Functions
- What is recursion in PHP?
- a) A function calling itself
- b) A function calling another function
- c) Infinite loop in a function
- d) Calling a function multiple times
- Which of the following is a base case in recursion?
- a) When a function calls itself
- b) When the recursion stops
- c) When an error occurs
- d) None of the above
- What will the following recursive function return?
function factorial($n) { if ($n <= 1) return 1; else return $n * factorial($n - 1); } echo factorial(4);- a) 10
- b) 12
- c) 24
- d) 16
- What can happen if a recursive function does not have a base case?
- a) Infinite loop
- b) Compilation error
- c) Memory overflow
- d) None of the above
- What is the maximum recursion depth in PHP by default?
- a) 100
- b) 256
- c) 512
- d) 1000
- How can you prevent infinite recursion in PHP?
- a) By defining a base case
- b) By using global variables
- c) By using a static keyword
- d) By limiting function calls
5. Built-in PHP Functions
- Which function is used to get the length of a string in PHP?
- a) strlen()
- b) length()
- c) strlength()
- d) sizeOf()
- What is the purpose of
isset()function?- a) Check if a variable is set and not null
- b) Check if a variable is false
- c) Check if a variable is empty
- d) Check if a variable is undefined
- What does the
explode()function do?- a) Joins array elements into a string
- b) Splits a string into an array
- c) Removes elements from an array
- d) Reverses a string
- How do you round a number to the nearest integer in PHP?
- a) round()
- b) ceil()
- c) floor()
- d) int()
- What is the output of the following code?phpCopy code
echo strtoupper("hello world");- a) hello world
- b) Hello World
- c) HELLO WORLD
- d) Error
- Which function is used to include a file in PHP?
- a) add()
- b) include()
- c) require_once()
- d) Both b and c
Answers
| QNo | Answer |
|---|---|
| 1 | b) function |
| 2 | c) functionName() |
| 3 | c) _function |
| 4 | c) Only with arrays |
| 5 | b) null |
| 6 | a) Using & |
| 7 | a) Error |
| 8 | d) function myFunction($param = 2) |
| 9 | a) Yes, using type hinting |
| 10 | a) function myFunction(): int |
| 11 | c) 8 |
| 12 | d) All of the above |
| 13 | b) Local |
| 14 | d) All of the above |
| 15 | b) Preserves the value of a variable between function calls |
| 16 | b) 15 |
| 17 | a) Yes, but only one is accessible |
| 18 | b) It stores all global variables |
| 19 | a) A function calling itself |
| 20 | b) When the recursion stops |
| 21 | c) 24 |
| 22 | c) Memory overflow |
| 23 | d) 1000 |
| 24 | a) By defining a base case |
| 25 | a) strlen() |
| 26 | a) Check if a variable is set and not null |
| 27 | b) Splits a string into an array |
| 28 | a) round() |