Below is what I have for the code so far. I need help with task 3 and 4. Also I

Question

Below is what I have for the code so far. I need help with task 3 and 4. Also I don't understand why my calculations aren't adding up correctly. The first is supposed to be 97.5 and I keep getting 97. The second is supposed to be 100 and I am getting 0.

Added are the specific directions for task 3 and 4.

Task #3 Working with Strings
1. Use the charAt method to get the first character in firstName and store it in a variable called firstInitial (you will need to declare any variables that you use).
2. Print out the user’s first initial. 3. Use the toUpperCase method to change the fullName to all capitals and
store it back into the fullName variable
4. Add a line that prints out the value of fullName and how many characters (including the space) are in the string stored in fullName (use the method length to obtain that information).
5. Compile, debug, and run. The new output added on after the output from the previous tasks should have your initials and your full name in all capital letters.
Gaddis_516907_Java 4/10/07 2:10 PM Page 14
Chapter 2 Lab Java Fundamentals 15
Task #4 Using Predefined Math Functions
1. Add a line that prompts the user to enter the diameter of a sphere.
2. Read in and store the number into a variable called diameter (you will need to declare any variables that you use).
3. The diameter is twice as long as the radius, so calculate and store the radius in an appropriately named variable.
4. The formula for the volume of a sphere is V = 4pr3
3
Convert the formula to Java and add a line which calculates and stores the value of volume in an appropriately named variable. Use Math.PI for p and Math.pow to cube the radius.
5. Print your results to the screen with an appropriate message.
6. Compile, debug, and run using the following test data and record the results.


Program:


import java.util.Scanner;

/**
This program demonstrates how numeric types and operators behave in Java
*/


public class NumericTypes
{
public static void main (String [] args)
{
Scanner keyboard = new Scanner(System.in);

//identifier declarations
final int NUMBER = 2 ; // number of scores
final int SCORE1 = 100; // first test score
final int SCORE2 = 95; // second test score
final int BOILING_IN_F = 212; // freezing temperature
int fToC; // temperature in celsius
int average; // arithmetic average
String output; // line of output to print out
String firstName;
String lastName;
char letter;

//TASK #2 declare variables used here
//TASK #3 declare variables used here
//TASK #4 declare variables used here

// Find an arithmetic average
average = (SCORE1 + SCORE2) / NUMBER;
output = SCORE1 + " and " + SCORE2 + " have an average of "
+ average;
System.out.println(output);

// Convert Fahrenheit temperatures to Celsius
fToC = (BOILING_IN_F - 32) * (5/9);
output = BOILING_IN_F + " in Fahrenheit is " + fToC
+ " in Celsius.";
System.out.println(output);
System.out.println(); // to leave a blank line

// ADD LINES FOR TASK #2 HERE

// prompt the user for first name
System.out.print(" What is your first name?");
// read the user's first name
firstName = keyboard.nextLine();

// prompt the user for last name
System.out.print(" What is your last name?");
// read the user's last name
lastName = keyboard.nextLine();

// print out the user's full name
System.out.println(""+ firstName + " " + lastName+"");

System.out.println(); // to leave a blank line

// ADD LINES FOR TASK #3 HERE

// get the first character from the user's first name
// print out the user's first initial
// convert the user's full name to all capital letters
// print out the user's full name in all capital letters

System.out.println(); // to leave a blank line

// ADD LINES FOR TASK #4 HERE
// prompt the user for a diameter of a sphere
// read the diameter
// calculate the radius
// calculate the volume
// print out the volume
}
}

Explanation / Answer

Task 3: letter=firstName.charAt(0); System.out.println(letter); System.out.println(firstName.toUpperCase()+lastName.toUpperCase()); Task 4: System.out.print("Diameter of a sphere: "); double d=Double.parseDouble(scan.nextLine()); double r=d/2; double v=4.0/3*Math.pow(r,3)*Math.PI; System.out.println(Volume is: "+v); The other parts: Basically what's going wrong is that you have the variables declared as integers. When you find the average of 100 and 95, you get 97.5. However, int variables can only hold integers, so it will truncate the decimal and you end up with 97. Declare the scores and average as double or float and you will be fine. Same with the temperature. It's multiplying all of that by 5/9, which evaluates, as an integer, to 0. Declare the temperatures as doubles and change (5/9) to (5.0/9).

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