Programming Fundamentals/Conditions/Compound Conditions

Compound conditions perform different computations or actions depending on whether multiple combined programmer-specified Boolean conditions evaluate to true or false. This activity introduces compound conditions. This activity will help you understand how to use compound conditions in a program.

Objectives

 * Understand compound condition concepts.
 * Understand how compound conditions are specified in a program.
 * Create truth tables for "and" and "or" logical operators.
 * Single-step through a program to observe nested condition execution.

Prerequisites
Learners should already be familiar with nested conditions.

Introduction


Review the flowchart example on the right.

Questions

 * What flowcharting symbol is used to indicate a condition?
 * How are compound conditions structured?
 * What is the difference between "and" and "or"?
 * What are truth tables?
 * What do "and" and "or" truth tables include?

Activity
With a partner, perform the following:
 * 1) Using a visual programming language, create a program matching the flowchart on the right.
 * 2) Save the program.
 * 3) Test the program to verify that it works correctly.
 * 4) Trade places, so that both partners have an opportunity to "drive" the visual programming environment.
 * 5) Change the environment to use a slow run speed and/or step through the program one shape at a time.
 * 6) Working together, identify the compound conditions that would be used to either convert Fahrenheit temperature to Celsius or convert Celsius temperature to Fahrenheit, depending on user choice.

Applications

 * Identify specific steps which must be followed when creating a program using compound conditions.
 * Discuss your activity experience with your classmates. What surprised you? What have you learned that you can apply to your own school or work environment?