Since the introduction of the Java Collections Framework with JDK 1.2 , ... Java arrays employ C-like zero-based indexes and so using an index of 0 obtains the first element.

Java 1.2 introduced the collection classes that we all know and love, ... Collections and arrays can be used to generate streams–but beware: Streams are not collections that store elements!

The Parallel Old Collector (‑XX:+UseParallelOldGC) , the default since Java 7u4, uses multiple threads for minor collections and multiple threads for major collections.