The Java Language

CS 161 - Java

Assignment for Next Time

Reading

Chapter 4 - Classes, Objects, and Methods
Chapter 5 - Programming with Classes and Methods

Homework

Goal:

Write a simple Java program from scratch;
Learn how to write a Java class with fields and methods.

Purpose:

To start thinking like a programmer to break a problem into smaller pieces.
To start getting the computer to calculate answers. To start learning to be exact when giving the computer instructions.

Instructions

Do the following:

Write a Java class named Employee. This class should have the following instance variables:
- an ID value
- the name of a person associated with the Employee
- a field to store a value for the annual salary
- a field to store a reference to another Employee object
  (for the Employee's boss, eventually)
Write methods with the following signatures
- a main method to start things off with the signature:
```
public static void main (String [] args)
```
  see below for what main should do.
- a public constructor for the class that will insure that Employee objects always have a name field with the signature
```
public Employee( String name)
```
- a method to set an Employee object's salary field with the signature
```
public void setSalary( double value )
```
- a method to get an Employee object's current salary field value with the signature
```
public double getSalary( )
```
- a method to set an Employee object's field referencing another Employee object with the signature
```
public void setBoss ( Employee boss )
```
- a method to return a String identifying the field contents of an Employee with the signature
```
public String toString()
```
The main method for this class should:
1. create a single instance of the Employee class,
2. assign a name and a salary value (any value), using the constructor and the setSalaray() methods
3. Access the current salary value (using the getSalary() method) and increase the Employee's salary by 10% using the setSalary method again.
4. then have the Employee object identify itself and it's current salary value.

Hint: Do the reading assignment before doing the homework.

In following assignments you are going to create several Employee objects. This assignment's goal is to create an object that will store information about a single employee. Next week we'll explore ways to create a number of Employee objects.

You should not do everything in the main method, do only what is asked for in the main method. Look at the in-class examples as a model for how the Employee class should be created.

Do only what is asked above. Do not add any extra code to prompt for input or otherwise add capabilities not asked for, simply use your name and whatever salary value you choose in the program. Be sure to create methods with the signatures requested. Output similar to the following is all the Employee class needs to produce:

Joe Student salary: 55000

Hint: To start, create the outline of your class definition by defining empty methods with the signatures listed above. Compile it to be sure the outline is in the right form. Then go back and start filling in the details of each method. Compile often so you can correct errors easily.

Hand in listings of your source file, and the usual transcript of its execution.

jwd