juniorRust
What is a Vec in Rust?
Updated May 24, 2026
Short answer
Vec is a growable array stored on the heap.
Deep explanation
Vectors dynamically resize and store elements contiguously in memory, providing efficient indexing and iteration.
Real-world example
Storing lists of user IDs or logs.
Common mistakes
- Assuming fixed size like arrays.
Follow-up questions
- How does Vec grow?
- Is Vec contiguous?