CS 163/164, Summer 2018

Lab 8 - Control Loops Continued

Tuesday, Jun. 26th

Here are the instructions for the lab:

Make sure you are in Workspace not QuizSpace
Create a project called R8 in Eclipse.
Create a class called R8 in the project R8 with a main method.
Copy the R8.java file into the R8 project source (~/workspace/R8/src).
Copy the data.txt file into the R8 project (~/workspace/R8).
Write the rest of your code in the main method, below the code shown.

import java.io.File;
import java.io.IOException;
import java.util.Scanner;

public class R8 {

    public static void main(String[] args) {

        // Declare variables
        int int0=0, int1=0;
        double real0=0.0, real1=0.0;
        char char0=' ', char1=' ', char2=' ';
        String string0="", string1="", string2="";
        
        try {

            // Open input stream
            Scanner scan = new Scanner(new File("data.txt"));

            // Read contents
            string0 = scan.nextLine();
            string1 = scan.nextLine();
            string2 = scan.nextLine();
            char0 = scan.next().charAt(0);
            char1 = scan.next().charAt(0);
            char2 = scan.next().charAt(0);
            int0 = scan.nextInt();
            int1 = scan.nextInt();
            real0 = scan.nextDouble();
            real1 = scan.nextDouble();

            // Close input stream
            scan.close();

        } catch (IOException e) {
            System.out.println("Cannot read file: data.txt");
            System.exit(0);
        }
        
        // PUT CODE HERE!
    }
}

We are going to kind of treat this like a programming quiz, except the TA will actually answer your questions!
You may edit the data file to test with different values.
Make sure your R8.java compiles and produces exactly 9 lines of output.
Show your lab to the TA for credit, as usual.

Note: The variables have already been defined and read from a file in the provided code, do not redeclare or assign your own values to the variables! Start with the provided code, then add your code below to do steps A-I. Do not print anything except what is specified below. You are free to open data.txt in Eclipse to see its contents.

IMPORTANT: Do the steps in order and make sure that each step A-I produces exactly one line of output! Add an empty System.out.println() if you cannot do one of the steps. HINT: Add a comment for each step before coding, and check the output after coding.

A) Print an expression that adds the product of int0 multiplied by 17 to the product of int1 multiplied by 7.
B) Print an expression that subtracts real0 from real1, then divides the result by 4.321.
C) Print real1 to the fifth power using Math.pow() with exactly 6 digits after the decimal.
D) Print the 4th character of string0, the 3rd character of string1, and the last character of string2, separated by commas. The code should work regardless of the length of string2!
E) Print the length of string1 added to the ASCII value of the first character of string1. HINT: Type cast the first character of string1 to get an integer before the addition.
F) Print the product of the ASCII values of char0, char1, and char2.
G) Print the boolean that is returned from using a comparison operator to check whether string2 is equal to "Hello World!".
H) Write a conditional (if/else if/else) statement as follows:

Print "Starts with uppercase letter." if string1 starts with an uppercase letter.

Print "Starts with lowercase letter." if string1 starts with a lowercase letter.

Otherwise print "Does not start with a letter."
I) Write a switch statement as follows:

The switch statement should check the value of char1.

If char1 equals '$', '@', or '#', print "Special Character".

If char1 equals '2', '4', '6', or '8', print "Even Digit".

If char1 equals '1', '3', '5', '7', or '9', print "Odd Digit".

If char1 equals 'a', 'e', 'i', 'o', or 'u', print "Vowel Letter".

Otherwise using System.out.println() to print the string "Unknown character".