Variable scope in functions in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is variable scope in PHP functions?

Variable scope defines where a variable can be accessed or used in the code. In PHP, variables inside functions are local by default and cannot be accessed outside the function.

beginner

What happens if you try to use a variable declared outside a function inside that function without any special keyword?

The function will not see the outside variable because variables inside functions are local by default. You need to use the global keyword or pass the variable as a parameter to access it.

beginner

How do you access a global variable inside a PHP function?

Use the global keyword inside the function before the variable name. This tells PHP to use the variable from the global scope.

intermediate

What is the static keyword used for in PHP functions?

The static keyword keeps a local variable's value between function calls. It means the variable does not reset each time the function runs.

beginner

Explain the difference between local and global variables in PHP.

Local variables exist only inside the function where they are declared. Global variables exist outside functions and can be accessed anywhere if declared global inside functions.

What keyword allows a function to access a variable declared outside it?

A global

B local

C static

D public

The global keyword tells the function to use the variable from the global scope.

What is the scope of a variable declared inside a function without any keyword?

A Global

B Public

C Static

D Local

Variables declared inside functions are local to that function by default.

Which keyword keeps a variable's value between function calls?

A global

B local

C static

D const

The static keyword preserves the variable's value between calls.

If you want to use a global variable inside a function without global, what is a good alternative?

A Pass it as a function parameter

B Declare it again inside the function

C Use <code>static</code> keyword

D Use <code>const</code> keyword

Passing the variable as a parameter lets the function use its value without needing global.

What happens if you try to access a local variable outside its function?

A It works fine

B It causes an error or undefined variable

C It accesses the global variable

D It converts to static

Local variables only exist inside their function and cannot be accessed outside.

Explain how variable scope works inside PHP functions and how to access variables from outside the function.

Think about where variables live and how to share them with functions.

Describe the purpose of the static keyword in PHP functions and give an example of when it might be useful.

Consider a counter that remembers its value each time a function runs.