Question

^{This needs to be in Java}

^{implementing Insertion Sort and displaying the floats sorted.}

^{Sample Output: (green is user input)}

Please select one of the following:
1: Initialize a default array
2: To specify the max size of the array
3: Add value to the array
4: Display values in the array
5: Display the average of the values
6: Enter multiple values
7: Read values from file
8: Save values to file
9: Sort the array
10: To Exit

^{import java.io.File; import java.io.FileNotFoundException; import java.io.PrintWriter; import java.util.Scanner;}

^{class Numbers {}

      ^{private float[] numbers;}

      ^{private int numItems = 0, size = 1;}

      ^{public Numbers() {}

            ^{numbers = new float[size];// default size }}

      ^{public Numbers(int size) {}

            ^{this.size = size;}

            ^{numbers = new float[size]; }}

      ^{public void addValue(Scanner scanner, boolean fromKeyboard) {}

            ^{if (fromKeyboard)}

                  ^{System.out.print("Enter value: ");}

            ^{float value = scanner.nextFloat();}

            ^{numbers[numItems++] = value;}

            ^{if (numItems >= size) {}

                  ^{float[] temp = new float[size + 5];}

                  ^{for (int i = 0; i < numItems; i++) {}

                        ^{temp[i] = numbers[i];                  }}

                  ^{numbers = temp; } }}

      ^{public float calcAverage() {}

            ^{float sum = 0;}

            ^{for (int i = 0; i < numItems; i++) {}

                  ^{sum += numbers[i];// calculating sum of the snumbers in the array }}

            ^{return (float) sum / numItems;// calculating average }}

      ^@Override

      ^{public String toString() {}

            ^{String data = "";}

            ^{for (int i = 0; i < numItems; i++) {}

                  ^{data += numbers[i] + "\n"; }}

            ^{return data; }}

      ^{public void addMultiple(Scanner scanner, boolean fromKeyboard) {}

            ^{if (fromKeyboard) {}

                  ^{System.out.print("How many values do you wish to add? "); }}

            ^{int n = scanner.nextInt();}

            ^{for (int i = 0; i < n; i++) {}

                  ^{addValue(scanner, fromKeyboard);}

            ^{} }}

      ^{public void loadData(Scanner scanner) {}

            ^{System.out.println("Name of the file to read from:");}

            ^{String name = scanner.next();}

            ^{try {}

                  ^{Scanner fileScanner = new Scanner(new File(name));}

                  ^{addMultiple(fileScanner, false);}

            ^{} catch (FileNotFoundException e) {}

                  ^{System.out.println("File not found!");}

            ^{} catch (Exception e) {}

                  ^{System.out.println("Invalid file format!");}

            ^}

      ^}

      ^{public void saveData(Scanner scanner) {}

            ^{System.out.println("Name of the file to save to:");}

            ^{String name = scanner.next();}

            ^{try {}

                  ^{PrintWriter writer = new PrintWriter(new File(name));}

                  ^{writer.println(numItems);}

                  ^{for (int i = 0; i < size; i++) {}

                        ^{writer.println(numbers[i]);}

                  ^}

                  ^{writer.close();}

            ^{} catch (FileNotFoundException e) {}

                  ^{System.out.println("File cant be opened!");}

            ^{} }}}

^{public class Test {// driver class}

      ^{public static void main(String[] args) {}

            ^{Numbers obj = new Numbers();}

            ^{Scanner sc = new Scanner(System.in);}

            ^{while (true) {// infinte loop}

                  ^{System.out.print("Please select one of the following:\r\n"}

                              ^{+ "1: Initialize a default array\r\n"+ "2: To specify the max size of the array\r\n" + "3: Add value to the array\r\n" + "4: Display values in the array\r\n" + "5: Display the average of the values\r\n" + "6: Enter multiple values\r\n" + "7: Read values from file\r\n" + "8: Save values to file\r\n" + "9: To Exit\r\n" + "> ");}

                  ^{int choice = sc.nextInt();// taking user choice}

                  ^{sc.nextLine();}

                  ^{switch (choice) {}

                  ^{case 1: System.out.println("New array initialized"); obj = new Numbers(); break;}

                  ^{case 2: System.out.print("Enter new size of the array: ");int size = sc.nextInt(); sc.nextLine(); obj = new Numbers(size); break;}

                  ^{case 3: obj.addValue(sc, true); break;}

                  ^{case 4: System.out.println("Numbers are:\n" + obj); break;}

                  ^{case 5: System.out.println("Average is: " + obj.calcAverage()); break;}

                  ^{case 6: // adding multiple values from keyboard obj.addMultiple(sc, true);break;}

                  ^{case 7:// loading values from fileobj.loadData(sc);break;}

                  ^{case 8:// saving values to fileobj.saveData(sc); break;}

                  ^{case 9: System.out.println("Good Bye"); System.exit(0);// exiting the program}

                  ^{default: System.out.println("Invalid choice!"); break;  } } }}}

Answer 1

If you have any problem with the code feel free to comment. I have highlighted the changes in the code

Program

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

class Numbers {

   private float[] numbers;

   private int numItems = 0, size = 1;

   public Numbers() {

       numbers = new float[size];// default size
   }

   public Numbers(int size) {

       this.size = size;

       numbers = new float[size];
   }

   public void addValue(Scanner scanner, boolean fromKeyboard) {

       if (fromKeyboard)

           System.out.print("Enter value: ");

       float value = scanner.nextFloat();

       numbers[numItems++] = value;
       validateArraySize();
   }

   public void validateArraySize() {
       if (numItems >= size) {

           float[] temp = new float[size + 5];

           for (int i = 0; i < numItems; i++) {

               temp[i] = numbers[i];
           }

           numbers = temp;
       }
   }

   public float calcAverage() {

       float sum = 0;

       for (int i = 0; i < numItems; i++)

           sum += numbers[i];// calculating sum of the snumbers in the array }

       return (float) sum / numItems; // calculating average }
   }

   @Override
   public String toString() {

       String data = "";

       for (int i = 0; i < numItems; i++) {

           data += numbers[i] + "\n";
       }

       return data;
   }

   public void addMultiple(Scanner scanner, boolean fromKeyboard) {

       if (fromKeyboard) {

           System.out.print("How many values do you wish to add? ");
       }

       int n = scanner.nextInt();

       for (int i = 0; i < n; i++) {

           addValue(scanner, fromKeyboard);

       }
   }

   public void loadData(Scanner scanner) {

       System.out.println("Name of the file to read from:");

       String name = scanner.nextLine();

       try {

           Scanner fileScanner = new Scanner(new File(name));

           while (fileScanner.hasNext()) {
               float value = Float.parseFloat(fileScanner.nextLine());
               numbers[numItems++] = value;
               validateArraySize();
           }
           fileScanner.close();

       } catch (FileNotFoundException e) {

           System.out.println("File not found!");

       } catch (Exception e) {

           System.out.println("Invalid file format!");

       }

   }

   public void saveData(Scanner scanner) {

       System.out.println("Name of the file to save to:");

       String name = scanner.next();

       try {

           PrintWriter writer = new PrintWriter(new File(name));

           writer.println(numItems);

           for (int i = 0; i < size; i++) {

               writer.println(numbers[i]);

           }

           writer.close();

       } catch (FileNotFoundException e) {

           System.out.println("File cant be opened!");

       }
   }

   public void sortArray() {
       //performing insertion sort
       for (int i = 1; i < numItems; ++i) {
           float toInsert = numbers[i];
           int j = i - 1;
           while (j >= 0 && numbers[j] > toInsert) {
               numbers[j + 1] = numbers[j];
               j = j - 1;
           }
           numbers[j + 1] = toInsert;
       }
   }
}

public class Test {// driver class

   public static void main(String[] args) {

       Numbers obj = new Numbers();

       Scanner sc = new Scanner(System.in);

       while (true) {// infinte loop

           System.out.print("Please select one of the following:\r\n"

                   + "1: Initialize a default array\r\n" + "2: To specify the max size of the array\r\n"
                   + "3: Add value to the array\r\n" + "4: Display values in the array\r\n"
                   + "5: Display the average of the values\r\n" + "6: Enter multiple values\r\n"
                   + "7: Read values from file\r\n" + "8: Save values to file\r\n" + "9: Sort the array\r\n"
                   + "10: To Exit\r\n" + "> ");

           int choice = sc.nextInt();// taking user choice

           sc.nextLine();

           switch (choice) {

           case 1:
               System.out.println("New array initialized");
               obj = new Numbers();
               break;

           case 2:
               System.out.print("Enter new size of the array: ");
               int size = sc.nextInt();
               sc.nextLine();
               obj = new Numbers(size);
               break;

           case 3:
               obj.addValue(sc, true);
               break;

           case 4:
               System.out.println("Numbers are:\n" + obj);
               break;

           case 5:
               System.out.println("Average is: " + obj.calcAverage());
               break;

           case 6:
               obj.addMultiple(sc, true);
               break;

           case 7:
               obj.loadData(sc);
               break;

           case 8:
               obj.saveData(sc);
               break;

           case 9:
               obj.sortArray();
               break;

           case 10:
               System.out.println("Good Bye");
               System.exit(0);// exiting the program

           default:
               System.out.println("Invalid choice!");
               break;
           }
       }
   }
}

Output

Input