Kit Library / Computer Science / C Programming / Memory Management
Quick KitShared by a Veda learner · Generated with Veda AI
Veda Bites are swipeable micro-lessons — each one teaches exactly one idea. Here's a taste from this kit; the app has the full deck.
Structs side-by-side, unions overlap.
A struct stores all members side-by-side, each with its own memory. A union stores all members in the same memory space, so only one member is valid at a time.
↳ Structs keep all data accessible; unions save memory by sharing space.
Bundle different types into one.
A structure (`struct`) is a user-defined data type that groups different types of variables under one name. All members exist at the same time, each with its own memory location.
↳ A struct is a collection of related but distinct data fields.
Different types, same memory spot.
A union (`union`) allows storing different types in the same memory location. Only one member is active at a time; all members share the same starting address.
↳ A union is a single memory space that can hold one of several types.
Structures and unions in C are both ways to group data, but they differ fundamentally in memory layout and usage. Structures allocate separate memory for each member, allowing simultaneous access, while unions share memo...
~8 min · full explanation, examples & memory tricks in the app
12 questions laddered from warm-up to topper-level, each with an explanation. A taste:
What is the primary difference between a `struct` and a `union` in C?
BeginnerA struct stores all members side-by-side with separate memory; a union stores all members in the same memory space.
The core difference is that a struct allocates separate memory for each member, while a union shares a single memory space among all members.
Given `struct S { int a; char b; };` and assuming `int` is 4 bytes and `char` is 1 byte, what is the minimum possible size of `struct S` (ignoring padding)?
Beginner5 bytes
The size of a struct is at least the sum of its members' sizes: 4 + 1 = 5 bytes (padding may increase it).
Given `union U { int a; char b; };` and assuming `int` is 4 bytes and `char` is 1 byte, what is the size of `union U`?
Beginner4 bytes
A union's size equals the size of its largest member, which is the `int` at 4 bytes.
In a `union`, what happens when you write to one member after another member has been assigned?
IntermediateThe previous member's value is overwritten.
All members of a union share the same memory location, so writing to one overwrites the data of any previously active member.
22 flashcards in this kit — the app reviews them with spaced repetition so the right card returns on the right day.
Every game is built from this kit's own content — scores feed your mastery, so playing counts as studying.
The full Veda Bites deck, complete notes, spaced-repetition flashcards, leveled MCQs, tests and games for this kit — plus Daily Facts and the Arena, every day.
