What is the contract between equals() and hashcode()? Learn how these methods work together when comparing objects in Java.

If you are fortunate enough to be using JDK 7, the newly available Objects class is the obvious (at least to me) choice for implementing the “common” Java object methods such as equals (Object ...

This tutorial explains how a Java HashMap works internally and explores the challenges of implementing it, including buckets, collisions and hash codes.

While languages like Ruby provide the pertinent information you need, why can't Java provide a decent, useable, toString() method right out of the box?