This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
.length is a fundamental property of any array. It's "defined" in the Java Language Specification. Since an array is an Object, you can also call methods such as equals(), hashCode(), getClass(), notify(), wait(), etc.