It makes the code easier to read, allows the use of lambdas (in the case of stream()) and eliminates the need for an index variable and a get() operation required by the classic for loop. If, say, you wanted to print the contents of an ArrayList list using a classic for loop, it would look like this: for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } Using an enhanced for loop, it would look like this: for(String s: list) { System.out.println(s); } There is now no need to use an index variable or a get() operation. More on reddit.com

Sure. Say you have an array list of strings (ArrayList list), and you wanted to print out each of the elements in the list. You could do it one of two ways: for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } or method 2: for (String s : list) { System.out.println(s); } This second function is the enhanced for loop. So basically if you're iterating over a list or set, you don't have to write out the full old for loop syntax, you can just write the much more readable enhanced for-loop syntax. Its much more readable because the bounds of the for-loop are very clear (you're iterating over each element of the for loop from start to end) and you immediately have access to each element without calling .get(index). The downsides of the enhanced for-loop is that you don't have access to the index you're at without explicitly keeping track of it, and that it only works on objects that extend the Collections interface, so really only lists and sets. So no enhanced for loops on hashmaps or iterators. More on reddit.com

It's not used just to display arrays. It can be used for a variety of things (finding max in an array, finding number of elements that satisfy a criteria, etc). You sound like you are preparing for an exam or something. If so, the teacher using the phrase "enhanced" seems wrong. Should be called a foreach loop (even though each does not appear in the syntax). More on reddit.com

A mutator method modifies the state of an object. The state of an object is described by its attributes. Commonly, mutator methods refer to setter methods which allow the client code to modify the value of an object’s attribute. The mutator method encapsulates the object’s attribute while making it possible to change it. This is useful down the line since subclasses may have additional behaviour tied to modifying an attribute. For instance, you could model a person object with an age attribute. By supplying a mutator for the age attribute, client code can modify a person’s age. A subclass could override the mutator’s behaviour to notify observers that should be notified of changes on the person. Check out the observer pattern for more details on that. More on reddit.com