In this chapter, we introduced the reader to the classes from the Java Standard Library and Apache Commons that allow the manipulating of collections and arrays. Every Java programmer has to know the capabilities of the classes java.util.Collections, java.util.Arrays, org.acpache.commons.collections4.CollectionUtils, and org.acpache.commons.lang3.ArrayUtils.
In the next chapter, we are going to discuss classes that, together with classes discussed in this chapter, belong to a group of the most popular utilities that every programmer has to master in order to become an effective coder.