Why dynamic memory is needed - Quick Recap

Recall & Review

beginner

What is dynamic memory in C?

Dynamic memory is memory allocated during program execution using functions like malloc(), calloc(), and realloc(). It allows flexible use of memory based on program needs.

beginner

Why can't we always use static memory allocation?

Static memory allocation fixes memory size at compile time, which can waste memory or limit program flexibility if the exact size is unknown or changes during runtime.

beginner

How does dynamic memory help with unknown data sizes?

Dynamic memory lets programs allocate exactly the amount of memory needed at runtime, which is useful when data size is unknown or changes, like reading user input or files.

beginner

What happens if you don't free dynamic memory?

If dynamic memory is not freed using free(), it causes memory leaks, which waste memory and can slow down or crash programs over time.

beginner

Give a real-life example where dynamic memory is needed.

Imagine a photo app that loads pictures of different sizes. It can't reserve fixed memory for all photos, so it uses dynamic memory to allocate space as needed for each photo.

Which C function is used to allocate dynamic memory?

A malloc()

B printf()

C scanf()

D main()

malloc() allocates memory dynamically during program execution.

Why is dynamic memory allocation useful?

A It makes programs run faster always

B It fixes memory size at compile time

C It allows memory size to change during runtime

D It removes the need to free memory

Dynamic memory allows programs to allocate memory as needed during runtime.

What is a risk of not freeing dynamic memory?

A Faster execution

B Memory leaks

C More CPU usage

D Syntax errors

Not freeing dynamic memory causes memory leaks, wasting memory.

Static memory allocation is done when?

A During program execution

B After program ends

C Only in dynamic languages

D At compile time

Static memory is allocated at compile time and cannot change during execution.

Which scenario needs dynamic memory?

A User inputs unknown number of values

B Declaring constants

C Printing a fixed message

D Fixed size array known at compile time

When the number of inputs is unknown, dynamic memory lets you allocate space as needed.

Explain why dynamic memory is important in C programming.

Think about programs that don't know how much data they will handle before running.

Describe what can happen if dynamic memory is not properly managed.

Consider what happens if memory is allocated but never given back.