如何在 Java 中添加运行次数的摘要报告？

Question

I am trying to get a total report for how many times a user has done a problem in a calculator after they exit the program. I would like it to look like this:

Calculator Report
Addition problems: 3
Subtraction problems: 0
Multiplication problems: 2
Division problems: 1
Total problems: 6

Below is my code. The calculator part of the code works and I think I have set up the correct counting variables but cannot get it to create a report when the user exits.

import java.util.Scanner;
import java.math.*;

public class Calculator2
 {
 private static final Scanner askScanner = new Scanner(System.in);
 public static int answer;
 public static int firstNumber;
 public static int secondNumber; //makes variables for the whole class

 //Used for the Report at the end. 
 public static int addCount = 0;
 public static int subCount = 0;
 public static int mulCount = 0;
 public static int divCount = 0;


 public static void main(String[] args) {
    calculator();
    printReport();
 }

 public static void calculator() {


  
  while (true) {
  
     System.out.println("Basic calculator");
     System.out.println("Pick one:");
     System.out.println("(A)ddition");
     System.out.println("(S)ubtraction");
     System.out.println("(M)ultiplication");
     System.out.println("(D)ivision");
     System.out.println("\n(E)xit");
  
     String line = askScanner.nextLine().toUpperCase(); //Allows for any input to be a capitol letter.
     char pick = line.charAt(0);
  
  //uses the input of the user and directs it to the correct opertation
     if(pick == 'A') {
        addition();
     }
     else if(pick == 'S') {
        subtraction();
     }
     else if(pick == 'M') {
        multiplication();
     }
     else if(pick == 'D') {
        division();
     }
     else if(pick == 'E') {
        exit();
     }
     else {
        System.out.println("You need to choose A, S, M, D, or E");
        
     
     }
  } // end while


 }
 //asks the user for the 2 numbers
  private static void getNumbers() {
    System.out.print("Enter you first number: ");
    firstNumber = askScanner.nextInt();
    System.out.print("Enter your second number: ");
    secondNumber = askScanner.nextInt();
    askScanner.nextLine();  
   }
 //the different operations based off what the user wanted to do plus the operation itself
  public static void subtraction() {
    System.out.println("Subtraction");
    getNumbers();
    answer = firstNumber - secondNumber;
    System.out.println("This is the difference of the two numbers:  " + answer);
    subCount++;  
 }

   public static void addition() {
    System.out.println("Addition");
    getNumbers();
    answer = firstNumber + secondNumber;
    System.out.println("This is the sum of the two numbers:  " + answer);
    addCount++; 
 }

 public static void multiplication() {
    System.out.println("Multiplication");
    getNumbers();
    answer = firstNumber * secondNumber;
    System.out.println("This is the product of the two numbers  " + answer);
    mulCount++;  
 }

 public static void division() {
    System.out.println("Division");
    getNumbers();
    try{
       answer = firstNumber / secondNumber; 
       System.out.println("This is the quotient of the two numbers:    " + answer);
    }
    catch (ArithmeticException e) {
       System.out.println("Cannot divide by zero!! Please enter another number to divide by." );
    }
    divCount++; 
   
 }

 public static void exit() {
    System.exit(0);   
   }


 public static void printReport() {
  }
 }

Answer 1

The variables that you increment every time you call a calculator function are really nice. What I would is fill in the printReport() method like so

public static void printReport() {
    System.out.println("Calculator Report");
    System.out.println("Addition problems: " + addCount);
    System.out.println("Substraction problems: " + subCount);
    System.out.println("Multiplication problems: " + mulCount);
    System.out.println("Division problems: " + divCount);
    System.out.println("Total Problems: " + (addCount + subCount + mulCount + divCount));
}

And change the exit method to

public static void exit() {
    Calculator2.printReport();
    System.exit(0);
}

Be sure to call the printReport() method in the exit() method. And do it before the System.exit(0); line. Otherwise it won't execute.

If you want, you can copy this code. I implemented the methods for you:

import java.util.Scanner;
import java.math.*;

public class Calculator2
{
    private static final Scanner askScanner = new Scanner(System.in);
    public static int answer;
    public static int firstNumber;
    public static int secondNumber; //makes variables for the whole class

    //Used for the Report at the end.
    public static int addCount = 0;
    public static int subCount = 0;
    public static int mulCount = 0;
    public static int divCount = 0;


    public static void main(String[] args) {
        calculator();
        printReport();
    }

    public static void calculator() {
        while (true) {

            System.out.println("Basic calculator");
            System.out.println("Pick one:");
            System.out.println("(A)ddition");
            System.out.println("(S)ubtraction");
            System.out.println("(M)ultiplication");
            System.out.println("(D)ivision");
            System.out.println("\n(E)xit");

            String line = askScanner.nextLine().toUpperCase(); //Allows for any input to be a capitol letter.
            char pick = line.charAt(0);

            //uses the input of the user and directs it to the correct opertation
            if(pick == 'A') {
                addition();
            }
            else if(pick == 'S') {
                subtraction();
            }
            else if(pick == 'M') {
                multiplication();
            }
            else if(pick == 'D') {
                division();
            }
            else if(pick == 'E') {
                exit();
            }
            else {
                System.out.println("You need to choose A, S, M, D, or E");


            }
        } // end while


    }
    //asks the user for the 2 numbers
    private static void getNumbers() {
        System.out.print("Enter you first number: ");
        firstNumber = askScanner.nextInt();
        System.out.print("Enter your second number: ");
        secondNumber = askScanner.nextInt();
        askScanner.nextLine();
    }
    //the different operations based off what the user wanted to do plus the operation itself
    public static void subtraction() {
        System.out.println("Subtraction");
        getNumbers();
        answer = firstNumber - secondNumber;
        System.out.println("This is the difference of the two numbers:  " + answer);
        subCount++;
    }

    public static void addition() {
        System.out.println("Addition");
        getNumbers();
        answer = firstNumber + secondNumber;
        System.out.println("This is the sum of the two numbers:  " + answer);
        addCount++;
    }

    public static void multiplication() {
        System.out.println("Multiplication");
        getNumbers();
        answer = firstNumber * secondNumber;
        System.out.println("This is the product of the two numbers  " + answer);
        mulCount++;
    }

    public static void division() {
        System.out.println("Division");
        getNumbers();
        try{
            answer = firstNumber / secondNumber;
            System.out.println("This is the quotient of the two numbers:    " + answer);
        }
        catch (ArithmeticException e) {
            System.out.println("Cannot divide by zero!! Please enter another number to divide by." );
        }
        divCount++;

    }

    public static void exit() {
        Calculator2.printReport();
        System.exit(0);
    }


    public static void printReport() {
        System.out.println("Calculator Report");
        System.out.println("Addition problems: " + addCount);
        System.out.println("Substraction problems: " + subCount);
        System.out.println("Multiplication problems: " + mulCount);
        System.out.println("Division problems: " + divCount);
        System.out.println("Total Problems: " + (addCount + subCount + mulCount + divCount));
    }
}