Scope of variables in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the scope of a variable in C++?

The scope of a variable is the part of the program where the variable can be accessed or used.

beginner

What is the difference between local and global variables?

Local variables are declared inside a function or block and can only be used there. Global variables are declared outside all functions and can be used anywhere in the program.

intermediate

What happens if a local variable has the same name as a global variable?

The local variable 'shadows' the global variable inside its scope, so the local variable is used instead.

beginner

What is block scope in C++?

Block scope means a variable declared inside curly braces { } can only be used inside those braces.

beginner

Can a variable declared inside a function be accessed outside it?

No, variables declared inside a function are local to that function and cannot be accessed outside.

Where can a global variable be accessed in a C++ program?

A Nowhere, it is private

B Only inside the function where it is declared

C Anywhere in the program

D Only inside the block where it is declared

Global variables are declared outside all functions and can be accessed anywhere in the program.

What is the scope of a variable declared inside a for loop?

A Only inside the function

B Only inside the for loop block

C Entire program

D Global scope

Variables declared inside a for loop have block scope and exist only inside the loop.

If a local variable and a global variable have the same name, which one is used inside the function?

A Local variable

B Global variable

C Both at the same time

D None

The local variable shadows the global variable inside the function scope.

Can a variable declared inside a function be used in another function?

A Only if declared static

B Yes, always

C Only if passed as a parameter

D No, local variables are limited to their function

Local variables exist only inside the function where they are declared.

What keyword is used to declare a variable that keeps its value between function calls?

A static

B global

C const

D extern

The 'static' keyword makes a local variable keep its value between calls.

Explain the difference between local and global variable scope in C++.

Think about where you declare the variable and where you can use it.

Describe what happens when a local variable has the same name as a global variable.

Consider which variable the program uses inside the function.