Thread: My code-segment somehow executes again after I press RETURN, which isn't what I want

The program I am trying to make should have a menu to select from that looks like this:

Geometry Calculator
1. Calculate the Area of a Circle
2. Calculate the Area of a Rectangle
3. Calculate the Area of a Triangle
4. Quit
 
 
Enter your choice (1-4):

So, as you can see, the program is supposed to do math-calculations for a shape's surface-area. The
problem is that I can't get it to stop repeating the same question after it is finished. The code for the
program is below under the filenames AreaGiver.java (the main-program) and Geometry.java (the class
objects are made from for the main program). The java-comments will explain what I thought I was doing right, as well as the errors I realized in bold, parenthesized, capital-letters.

// This import-statement will be for Scanner-class input and output.
import java.util.Scanner;
 
// This import-statement will be for DecimalFormat-class numerical-setups.
import java.text.DecimalFormat;
 
public class AreaGiver
{
     public static void main(String[] args)
     {
          // Here is a variable-setup for the these matched-up reasons:
          int areaChoice;  // to hold the user's calculation-selection,
          double radius,   // the radius of a circle,
               length,        // the length of a rectangle,
               width,         // the width of the rectangle,
               base,          // the base of a triangle,
               height,        // the height of the triangle,
               area;          // the area of each shape,
 
          // to create a Scanner-class object named keys,
          Scanner keys = new Scanner(System.in);
 
          // and a DecimalFormat-class setup for the math-work results.
          DecimalFormat numSetup = new DecimalFormat("#,##0.00");
 
          // Here, a menu is displayed by these statements, so the
          // numerical-choice can be made by the user.
          System.out.println("Geometry Calculator");
          System.out.println("1. Calculate the Area of a Circle");
          System.out.println("2. Calculate the Area of a Rectangle");
          System.out.println("3. Calculate the Area of a Triangle");
          System.out.println("4. Quit");
          System.out.println();
          System.out.println();
          System.out.println("Enter your choice (1-4):");
          areaChoice = keys.nextInt();
 
          // This loop should execute each calculation-process based on the 
          // selection while the areaChoice-variable is outside the range of 1-4.
          // ([B]THE IF-STATEMENTS WILL REPEAT IF YOU PRESS ENTER.[/B])
          do
          {
               // This if statement will make the selection.
               if (areaChoice == 1)
               {
                    // Get the circle's radius.
                    System.out.println("What is the radius of your circle?");
                    radius = keys.nextDouble();
 
                    // Store the area in the area-variable for easier-reading.
                    area = Geometry.getCircularArea(radius);
 
                    // Display the circle's area.
                    System.out.println("Your circle's area is: " 
                                  + numSetup.format(area));
               }
 
               else if (areaChoice == 2)
               {
                    // Get the rectangle's length.
                    System.out.println("What is the length of your rectangle?");
                    length = keys.nextDouble();
 
                    // Get the rectangle's width.
                    System.out.println("What is the width of your rectangle?");
                    width = keys.nextDouble();
 
                    // Store the area in the area-variable for easier-reading.
                    area = Geometry.getRectangularArea(length, width);
 
                    // Show the area of the rectangle.
                    System.out.println("Your rectangle's area is: "
                                  + numSetup.format(area));
               }
 
               else if (areaChoice == 3)
               {
                    // Get the triangle's base.
                    System.out.println("What is the base of your triangle?");
                    base = keys.nextDouble();
 
                    // Get the triangle's height.
                    System.out.println("What is the height of your triangle?");
                    height = keys.nextDouble();
 
                    // Put the area in the area-variable for easier-reading.
                    area = Geometry.getTriangularArea(base, height);
 
                    // Show the triangle's area.
                    System.out.println("Your triangle's area is: "
                                  + numSetup.format(area));
               }
 
               else if (areaChoice == 4)
               {
                    // Show that the program ends here.
                    System.out.println("Program ending");
               }
 
               else
               {
                    // Show an error-message to get a number within the range of 1-4.
                    System.out.println("Enter a number within the range of"
                                        + " 1-4.");
 
                    areaChoice = keys.nextInt();
               }
 
          } while (areaChoice <= 0 && areaChoice >= 5);  // Here, make the choice the user made.
     }
}

// Use this Scanner-class import-statement for output.
import java.util.Scanner;
 
public class Geometry
{
     // The getCircularArea-method should calculate the area of a circle
     // and give an error-message to get the right number-type.
     public static double getCircularArea(double radius)
     {
          // Create a Scanner-class object for output.
          Scanner keys = new Scanner(System.in);
 
          // Give an error-message for a value of 0 or below.
          // ([B]THIS LOOP WILL KEEP REPEATING UNLESS YOU PRESS CTRL + C.[/B])
          while (radius <= 0)
          {
               System.out.println("Do not enter a value of 0 or below.");
          }
 
          // Return the circle's area.
          return Math.PI * Math.pow(radius, 2.0);
     }
 
     // The getRectangularArea-method should calculate the area of a rectangle
     // and give an error-message to get the right number-type.
     public static double getRectangularArea(double length, double width)
     {
          // Create a Scanner-class object for output.
          Scanner keys = new Scanner(System.in);
 
          // Give an error-message for a value of 0 or below.
          // ([B]THIS LOOP WILL KEEP REPEATING UNLESS YOU PRESS CTRL + C.[/B])
          while (length <= 0 && width <= 0)
          {
               System.out.println("Do not enter values of zero or below.");
          }
 
          // Return the rectangular-area.
          return length * width;
     }
 
     // The getTriangularArea-method should calculate the area of a triangle
     // and give an error-message to get the right number-type.
     public static double getTriangularArea(double base, double height)
     {
          // Create a Scanner-class object for output.
          Scanner keys = new Scanner(System.in);
 
          // Give an error-message for a value of 0 or below.
          // ([B]THIS LOOP WILL KEEP REPEATING UNLESS YOU PRESS CTRL + C.[/B])
          while (base <= 0 && height <= 0)
          {
               System.out.println("Do not enter values of zero or below.");
          }
 
          // Return the triangular-area.
          return base * height * 0.5;      
     }
}

If there is anything erroneous about the posting's presentation, let me know. (I'm new to this.)

Please do not duplicate threads. I have merged your threads (somehow the merge went a bit too far and merged 3 posts into one, I edited your post above to avoid confusion - sorry about that).

Check the while condition

while (areaChoice <= 0 && areaChoice >= 5);

a value cannot be <= 0 and >= 5

Two things I noticed.

1.) You never actually told it

System.exit(0); for your ending code, so it won't actually ever end.

2.) If you put that menu to pop up inside the do while loop, then it might repeat if given a bad answer. In fact, it'll repeat if given a good answer too. As is, there's no way for the user to enter another value unless it's inside the loop.

3.) while (base <= 0 && height <= 0)
{
System.out.println("Do not enter values of zero or below.");
}

Assuming you don't want a base OR a height to be less than or equal to 0, you should change that && to ||

Otherwise it will only go through the loop if BOTH are less than or equal to 0.

Originally Posted by javapenguin

1.) You never actually told it

System.exit(0); for your ending code, so it won't actually ever end.

There is absolutely no reason the code should make a call to exit.

This thread is now solved. I was supposed to add an input-getting statement after my error-messages in Geometry.java and make a while-loop before the if-else-if statement in AreaGiver.java. All I needed were some of these responses.