August 18, 2011 · 1 min read
The [Collections](http://way2java.com/collections/collections-api-methods/) method **swap()** is very useful to swap two values in a programming code. For example, the prices of two different dates can be swapped. This method comes into existence with JDK 1.4.
June 26, 2011 · 3 min read
After knowing the meaning and purpose of [Collections framework](http://way2java.com/collections/java-collections-framework/), let us know the basic interfaces, derived classes and their properties. Java data structures are nothing but subclasses of **Collection** and **Map** interfaces. Following hierarchy gives all the interfaces of Collections framework.