Please see the information below its a question from Object First With JAVA 6th Edition.

Complete exercises 6.27 (p.220). The constructor for the MapTeser class should add two entries to the HashMap at the time of creation. Also create a class that uses Maptester class named MaptesterDemo, this class must use both functions mentioned in the exercise. Submit the MapTester.java and MapTesterDemo.java files. Note: You will have to write those two classes from scratch, they are not in the project files.

Question from book:

of the get and put Read the documentation whether the explanation matches your current understanding Cod Exercise 6.26 How do you check how many entries are contained in a ma resp Exercise 6.27 Create a class MapTester (either in your current project or in a new project). In it, use a HashMap to implement a contacts list similar to the one in the example above. (Remember that you must import java.util.HashMap.) In this class, implement two methods: public void enterNumber (String name, String number) and public String lookupNumber (String name) The methods should use the put and get methods of the HashMap class to implement their functionality Exercise 6.28 What happens when you add an entry to a map with a key that already exists in the map? Exercise 6.29 What happens when you add two entries same value and two different keys? to a map with the Exercise 6.30 How do you check whether a given key is co (Give a Java code example.)