Programming Fundamentals/Conditions/Nested Conditions

Nested conditions perform a sequence of different computations or actions depending on whether programmer-specified Boolean conditions evaluate to true or false. This activity introduces nested conditions. This activity will help you understand how to use nested conditions in a program.

Objectives

 * Understand nested condition concepts.
 * Understand how nested conditions are specified in a program.
 * Single-step through a program to observe nested condition execution.

Prerequisites
Learners should already be familiar with conditions.

Introduction


Review the flowchart example on the right.

Questions

 * What flowcharting symbol is used to indicate a condition?
 * How are nested conditions structured?

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 nested 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 nested 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?