In this course, you'll explore the Map interface and the different Map implementations available in Java. You'll learn how the Map is not a collection at all, but how it can be used to associate keys and values, and obtain collection objects that represent those keys and values. You'll see how no duplicates are allowed in keys, which effectively constitute a Set. You'll explore three implementations of the Map interface - HashMap, LinkedHashMap, and TreeMap. Next, you'll learn the finer points of how these map implementations check for duplicates. Finally, you'll examine the correct implementations of the .equals, .hashCode, and .compareTo methods in objects that are to be stored in maps.
Advanced Features in Java: Working with Maps in Java
discover the key concepts covered in this course
describe how maps work and how they are not quite collections but are an important part of the Java Collections API
demonstrate that custom objects can be keys or values in maps, but that in order to ensure that there are no duplicates you have to override the .hashCode and .equals methods of those contained objects correctly
recognize that maps are not collections with a series of instanceof checks and a series of comparisons
recognize how maps work and that they are very similar to their set counterparts