Extern with Initializer

What this C++ extern and initializer question tests

This is a medium-difficulty C++ language-knowledge question that probes your understanding of how extern declarations interact with variable initialization across translation units. It's the kind of problem that separates candidates who've worked with multi-file C++ projects from those who've only read the spec.

To solve it, you need to reason carefully about the difference between declaring and defining a variable, how the linker resolves symbols across compilation units, and the order in which initializers run. The question rewards precise knowledge of C++ scoping rules and the one-definition rule (ODR).

• External linkage vs. internal linkage
• Declaration versus definition
• Initialization order in multi-unit programs
• The one-definition rule (ODR)