CS173: Intro to Computer Science - Iteration with the do Loop

Activity Goals

The goals of this activity are:
  1. To be able to explain the uses of the do loop structure
  2. To be able to apply boolean expressions to iterative structures via the do loop

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, and compare with your group to prepare for our whole-class discussion. 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: The do Loop with User Input

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import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        int value = 7;
        int guess = -1;
 
        // Used to read the user’s input from the console
        Scanner input = new Scanner(System.in);
 
        do {
            System.out.println("Can you guess my number?");
            guess = input.nextInt(); // read an integer from the keyboard
        } while(guess != value);
 
        System.out.println("You got it!");
    }
}

Questions

  1. Using this program structure as a template, write a program to ask the user to enter a menu option between 1 and 4. Print out one of four different messages depending on the menu option they choose, and if they do not enter a number between 1 and 4, continue prompting them until they do so.

Submission

I encourage you to submit your answers to the questions (and ask your own 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. You can find the link to the class notebook on the syllabus.

For Additional Practice

Feel free to visit these resources for additional practice exercises.