Java Map internals: a complete guide for juniors

Table of contents Why does Map exist? What would life be without it? HashMap: the street analogy hashCode() and equals() explained Collisions: when two people share a house Load factor and resizing The other Map types The one rule you must never break Interview problems where Map is the answer SECTION 1. Why does Map even exist? Before touching any internals, let's nail the real problem Map was built to solve because if you understand the problem, everything else makes sense automatically. Imagi