C language concept — can a structure be nested inside another structure?\n\nStatement: A structure can be nested inside another structure.

Introduction / Context:
Nested (or composite) aggregates are common in data modeling. This item checks whether C permits struct-within-struct design, which is frequently used for grouping related fields hierarchically.

Given Data / Assumptions:

• The statement claims a structure may be nested inside another structure.
• We consider standard, portable C.

Concept / Approach:
Standard C allows a struct member to be another struct type by value. This is a straightforward inclusion where the outer struct contains the entire inner struct as a sub-object. Self-embedding by value is not allowed because it would make the size infinite, but nesting different struct types (or the same via pointers) is fine.

Step-by-Step Solution:

Verification / Alternative check:
Compilers handle nested structs routinely; accessing fields uses dot chaining like p.addr.pin.

Why Other Options Are Wrong:

• Incorrect / Not allowed: Contradict the standard.
• Only via pointers: Unnecessarily restrictive; by-value nesting is allowed for different types.

Common Pitfalls:
Trying to embed a struct inside itself by value (invalid). Use a pointer for self-reference instead.

Final Answer:
Correct