1. How do you declare a function in PHP?
a) function myFunction() { … }
b) declare myFunction() { … }
c) create myFunction() { … }
d) newFunction myFunction() { … }
Answer:
a) function myFunction() { … }
Explanation:
Functions in PHP are declared using the 'function' keyword followed by the function name and parentheses.
2. Can PHP functions return a value?
a) Yes, using the return statement
b) No, PHP functions cannot return values
c) Only if specified at the time of function declaration
d) Only integer values can be returned
Answer:
a) Yes, using the return statement
Explanation:
PHP functions can return a value using the 'return' statement.
3. Which of the following is a valid function name in PHP?
a) 2myFunction
b) my_function
c) my function
d) myFunction!
Answer:
b) my_function
Explanation:
Function names in PHP can contain letters, numbers, and underscores, but they cannot start with a number or contain spaces and special characters.
4. How are arguments passed to a function in PHP?
a) Inside square brackets []
b) Inside curly braces {}
c) Inside parentheses ()
d) Separated by commas, without any brackets
Answer:
c) Inside parentheses ()
Explanation:
Arguments are passed to a PHP function inside parentheses, separated by commas.
5. What is a default argument value in a PHP function?
a) An argument that must be provided
b) An argument that is optional and has a predefined value
c) The first argument in every function
d) An argument that sets default settings for the function
Answer:
b) An argument that is optional and has a predefined value
Explanation:
Default argument values allow a function to be called without explicitly passing all the parameters, using predefined values for missing arguments.
6. Can a PHP function call itself?
a) Yes, this is called recursion
b) No, functions cannot call themselves
c) Only in a loop
d) Only if it's a static function
Answer:
a) Yes, this is called recursion
Explanation:
A function that calls itself is known as a recursive function in PHP.
7. What is the scope of a function in PHP?
a) Global
b) Local to the file it's declared in
c) Local to the block it's declared in
d) Only within other functions
Answer:
a) Global
Explanation:
Functions in PHP have a global scope and can be called from anywhere in the script after they are declared.
8. How do you specify a type for a function's return value in PHP?
a) Using the type keyword
b) Before the function name
c) After the function's parameters, preceded by a colon
d) It is not possible to specify a return type
Answer:
c) After the function's parameters, preceded by a colon
Explanation:
Return types are specified after the function's parameters and a colon in PHP.
9. Which keyword is used to create an anonymous function in PHP?
a) anonymous
b) lambda
c) function
d) anon
Answer:
c) function
Explanation:
Anonymous functions are declared with the 'function' keyword without a name in PHP.
10. What is the purpose of the 'global' keyword inside a function in PHP?
a) To create a global variable
b) To access a global variable inside the function
c) To make the function global
d) To export a local variable to the global scope
Answer:
b) To access a global variable inside the function
Explanation:
The 'global' keyword is used inside a function to access a variable that is defined in the global scope.
11. Can PHP functions have optional parameters?
a) Yes, by defining default values for parameters
b) No, all parameters must be specified
c) Only if the function is declared static
d) Only in object-oriented PHP
Answer:
a) Yes, by defining default values for parameters
Explanation:
PHP functions can have optional parameters by providing default values for those parameters.
12. How do you call a PHP function by reference?
a) By prefixing the function name with &
b) By prefixing the argument with &
c) By using the reference keyword
d) PHP does not support calling functions by reference
Answer:
b) By prefixing the argument with &
Explanation:
In PHP, to call a function by reference, you prefix the argument with an ampersand (&).
13. What is variable scope in the context of a PHP function?
a) The accessibility of variables inside and outside functions
b) The ability to declare variables
c) The range of values a variable can hold
d) The duration for which a variable exists
Answer:
a) The accessibility of variables inside and outside functions
Explanation:
Variable scope refers to the accessibility of variables in different parts of the script, particularly inside and outside functions.
14. How can you pass an unlimited number of arguments to a PHP function?
a) Using variadic parameters with …
b) By declaring the function with an array parameter
c) By using the unlimited keyword
d) It is not possible in PHP
Answer:
a) Using variadic parameters with …
Explanation:
Variadic parameters, denoted by …, allow a function to accept an unlimited number of arguments.
15. What will happen if a PHP function does not contain a return statement?
a) The function will return null
b) The function will return false
c) The script will produce an error
d) The function will return true
Answer:
a) The function will return null
Explanation:
If a function does not contain a return statement, it implicitly returns null in PHP.