CODEWITHSUNDEEP
java
Kenneth Wise
Kenneth Wise

Reputation: 11

How do you get a Scanner to store and repeat in a while loop

I need to write a program which accepts non-negative double type of numbers as income amounts one by one unti l a negative number is entered , and the negative number ends the program. When the program is completed by entering a negative number , it prints out the minimum, average, and maximum for the set of entered incomes (excluding the last negative number be cause it only indicates the end of user input). 

package incomeapp;
import java.util.Scanner;

/**
 *
 * @author Kenneth
 */
public class IncomeApp {
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter an income (any negative number to quit: ");
        double sum = 0;
        int count = 0;
        double i = sc.nextDouble();
        while (i > 0){
            double nextDouble;     
            nextDouble = sc.nextDouble();
             if (i < 0){
                 break;
             }    
        }
    } 
}

Upvotes: 1

Views: 1073

Answers (2)

Batman25663
Batman25663

Reputation: 272

Try this:

import java.util.*;
public class HelloWorld{

     public static void main(String []args){
        Scanner sc = new Scanner(System.in);
            System.out.print("Enter an income (any negative number to quit: ");
            double sum = 0;
            double max = 0;
            double min = Double.MAX_VALUE;
            int count = 0;
            double nextDouble;
            while (sc.hasNext()) {    
                nextDouble = sc.nextDouble();
                max = Math.max(max, nextDouble);
                 if (nextDouble < 0){                        
                     break;
                 }else {
                    min = Math.min(nextDouble, min);
                    sum += nextDouble;
                    count++;
                 }
            }
       System.out.println("Average: " + sum/count);
       System.out.println("Min: " + min);
       System.out.println("Max: " + max);
     }
}

Upvotes: 0

Raniz
Raniz

Reputation: 11113

There's a few issues with your code here:

  1. You never actually increment either sum or count
  2. You read input into i before the loop, but then you read into nextDouble inside the loop and the loop condition only checks i - which never changes.
  3. You never print out the minimum, average, and maximum
  4. The condition in the while and if statements are redundant (apart from the if condition accepting 0 which the while condition doesn't)

Now, this seems very much like a programming assignment to me so I'm not going to post the complete code for you. Here's what you should do to fix your code though:

  1. Increment sum and count in the loop.
  2. Use either i or nextDouble - not both.
  3. Print the desired output after the loop

  4. Pick one way of terminating the loop. Here's two ideas on how to do it:

    double i = sc.nextDouble();
while (i > 0) {
    // Do something with i
    i = sc.nextDouble();
}

    or

    while (true) {
    double i = sc.nextDouble();
    if (i <= 0) {
        break;
    }
    // Do something with i
}

Upvotes: 1

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