Static storage class - Cheat Sheet & Quick Revision

Recall & Review

beginner

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

It makes the variable keep its value between function calls instead of being reinitialized each time the function runs.

beginner

How does a static variable inside a function differ from a normal local variable?

A normal local variable is created and destroyed each time the function runs, but a static variable is created once and keeps its value between calls.

intermediate

What is the effect of declaring a global variable as static in C?

It limits the variable's scope to the file where it is declared, so it cannot be accessed from other files.

beginner

Why would you use a static variable inside a function?

To remember information between function calls without using global variables, like counting how many times the function was called.

beginner

Can a static variable inside a function be accessed outside that function?

No, it has local scope limited to the function, but its value persists between calls.

What happens to a static variable inside a function after the function finishes?

A It keeps its value and exists until the program ends.

B It is destroyed and loses its value.

C It becomes a global variable.

D It resets to zero automatically.

A static variable inside a function keeps its value and exists for the entire program run.

Declaring a global variable as static means:

A It becomes a local variable.

B It can be accessed from any file.

C It is only accessible within the file it is declared.

D It is deleted after main() ends.

Static global variables have file scope, so they cannot be accessed from other files.

Which keyword in C makes a variable keep its value between function calls?

A static

B register

C extern

D auto

The static keyword makes a variable retain its value between calls.

If you want a variable to be visible only inside one source file, which keyword should you use?

A extern

B static

C auto

D register

Static limits the scope of global variables to the file they are declared in.

What is the initial value of a static variable if not explicitly initialized?

A Random garbage value

B One

C Depends on compiler

D Zero or NULL

Static variables are automatically initialized to zero if not set by the programmer.

Explain how the static storage class affects the lifetime and scope of variables in C.

Think about how long the variable exists and where it can be accessed.

Describe a practical example where using a static variable inside a function is helpful.

Imagine a function that needs to remember something each time it runs.