CS173: Intro to Computer Science - Overview of a Computer Program and Data Types

Activity Goals

The goals of this activity are:
  1. To identify the major components of a Java program, including a method and a class
  2. To explain that binary data uses "bits" of 1's and 0's to represent data of various types, both numeric and textual
  3. To identify primitive data structures and their uses
  4. To be able to create and compile a Java source file in a chosen development environment

The Activity

Directions

Consider the activity models and answer the questions provided. First reflect on these questions on your own briefly, before discussing and comparing your thoughts with your group. Appoint one member of your group to discuss your findings with the class, and the rest of the group should help that member prepare their response. Answer each question individually from the activity on the Class Activity Questions discussion board. After class, think about the questions in the reflective prompt and respond to those individually in your notebook. Report out on areas of disagreement or items for which you and your group identified alternative approaches. Write down and report out questions you encountered along the way for group discussion.

Model 1: Hello World

Annotated Hello World Java program example

Questions

  1. What do you think the curly braces represent and enclose?

Model 2: Your First Program

Questions

  1. What do you think the // characters represent?

Model 3: Primitive Data Types

Odometer rollover
Type Name
Use
Example
int
Whole number numeric values
int participants = 40;
double
Fractional or decimal numeric values (these are called "floating point" values)
double price = 5.95;
boolean
True/False
boolean raining = false;
char
A single character
char grade = 'A';
String
Textual data
String name = "Lee";

Questions

  1. What is the data type of the value "Hello World!"?
  2. Observe the odometer above. What is the place value of each of the digits in a decimal system? How would this odometer count if the only digits it could display were 1 and 0? What would each place value be then?
  3. How might a computer represent a whole number using only 1 and 0 digits? How do you use the decimal digits 0 through 9 to represent all whole numbers?
  4. How might a computer represent a whole number using only 1 and 0 digits? How do you use the decimal digits 0 through 9 to represent all whole numbers?
  5. How might a computer represent a True/False boolean?
  6. How might a computer represent the letter 'A' or the word "Hi!"?

Embedded Code Environment

You can try out some code examples in this embedded development environment! To share this with someone else, first have one member of your group make a small change to the file, then click "Open in Repl.it". Log into your Repl.it account (or create one if needed), and click the "Share" button at the top right. Note that some embedded Repl.it projects have multiple source files; you can see those by clicking the file icon on the left navigation bar of the embedded code frame. Share the link that opens up with your group members. Remember only to do this for partner/group activities!

Submission

Submit your answers to the questions using the Class Activity Questions discussion board. You may also respond to questions or comments made by others, or ask follow-up questions there. Answer any reflective prompt questions in the Reflective Journal section of your OneNote Classroom personal section.

For Additional Practice

Feel free to visit these resources for additional practice exercises.