How big is a pointer?

Understanding pointer sizes in C++ on 64-bit systems

This is a straightforward but essential C++ language knowledge question that tests whether you understand the memory model of modern architectures. It's the kind of foundational detail that interviewers expect you to know cold, especially in low-latency or systems-heavy roles where memory layout and object sizes matter.

The question probes your familiarity with how pointers are represented on 64-bit platforms, which directly impacts struct packing, cache alignment, and space overhead in data structures. Getting this right also helps you reason correctly about larger questions around sizeof operators, pointer arithmetic, and memory alignment constraints that come up in real interview problems.

• Relationship between architecture width and pointer representation
• The sizeof operator and its behavior on different platforms
• Memory alignment and struct layout implications