What is the difference between `WeakHashMap` and a regular `HashMap` with `WeakReference` values?

Question

Java Professional — Hard

What is the difference between `WeakHashMap` and a regular `HashMap` with `WeakReference` values?

Accepted Answer

WeakHashMap uses weak references for keys, automatically removing entries when keys are garbage collected. In contrast, a regular HashMap with WeakReference values keeps the key alive but allows the value to be collected.