Lifetime and scope comparison - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is scope in C programming?

Scope is the part of the program where a variable or function is accessible or visible.

beginner

What does lifetime of a variable mean in C?

Lifetime is the period during program execution when the variable exists in memory and holds a value.

intermediate

Compare local and global variable scope.

Local variables are accessible only inside the block or function they are declared in. Global variables are accessible throughout the entire program after their declaration.

intermediate

How does the lifetime of a local variable differ from a global variable?

Local variables exist only while the function or block runs. Global variables exist for the entire program run.

advanced

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

A static variable inside a function has a lifetime for the entire program run but its scope is limited to that function only.

Where is a local variable accessible in C?

A Throughout the entire program

B Only inside the block or function it is declared in

C Only inside the header files

D Nowhere, it is not accessible

Local variables are only accessible inside the block or function where they are declared.

What happens to a local variable's value after the function ends?

A It is copied to all other functions

B It remains stored in memory

C It becomes a global variable

D It is lost because the variable's lifetime ends

Local variables exist only while the function runs; after it ends, their values are lost.

What is true about a global variable's lifetime?

A It lasts only inside one function

B It lasts only during compilation

C It lasts for the entire program execution

D It lasts only inside a block

Global variables exist for the whole time the program runs.

What does the static keyword do to a variable inside a function?

A Keeps the variable alive for the whole program but limits its scope to the function

B Makes the variable global

C Deletes the variable after the function ends

D Makes the variable accessible everywhere

Static variables inside functions keep their value between calls but are only accessible inside that function.

Which variable has the widest scope in C?

A Global variable

B Local variable

C Static variable inside a function

D Function parameter

Global variables can be accessed anywhere after their declaration.

Explain the difference between scope and lifetime of a variable in C.

Think about where a variable can be used versus how long it exists.

Describe how a static variable inside a function behaves in terms of scope and lifetime.

Consider how static changes the usual local variable behavior.