Scope of variables - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the scope of a variable in C?

The scope of a variable in C 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 and can only be used within that function. Global variables are declared outside all functions and can be used anywhere in the program after their declaration.

intermediate

What happens if a local variable and a global variable have the same name?

The local variable will hide or override the global variable inside its scope (usually inside the function). Outside the function, the global variable is used.

beginner

What is block scope in C?

Block scope means a variable declared inside a pair of braces { } is only accessible inside those braces.

intermediate

What is the scope of a static variable inside a function?

A static variable inside a function keeps its value between calls but is only accessible inside that function.

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

A Only inside the block where it is declared

B Only inside the function where it is declared

C Anywhere in the program after its declaration

D Nowhere, global variables do not exist in C

Global variables are declared outside all functions and can be accessed anywhere after their declaration.

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

A Only inside the for loop block

B Entire program

C Only inside the function containing the loop

D Global scope

Variables declared inside the for loop block have block scope and are accessible only inside that block.

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

A Local variable

B Global variable

C Both variables are used simultaneously

D Compilation error

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

What does the static keyword do when used with a variable inside a function?

A Makes the variable global

B Makes the variable accessible only outside the function

C Deletes the variable after the function ends

D Keeps the variable value between function calls and limits scope to the function

Static variables inside functions retain their value between calls and are only accessible inside that function.

Which of these is NOT a valid scope type in C?

A Local scope

B Class scope

C Block scope

D Global scope

C does not have class scope because it is not an object-oriented language.

Explain the difference between local and global variables in C and give an example of each.

Think about where the variables are declared and where they can be used.

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

Consider which variable the program uses inside the function.