在 Java 中使用 do-while 循环查找序列中所有元素的总和，以数字 0 结尾

Question

I am a beginner. I appreciate if someone solves my problem in simple way in Java.

Problem: Find the sum of all elements of a sequence, ending with the number 0. The number 0 itself is not included into the sequence and serves as a sign of cessation. Sample Input: 3 6 8 0 and Sample Output: 17

I am writing following program:

 import java.util.Scanner;
 class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int sum = 0;
        do {
            sum += scanner.nextInt();
        } while (scanner.nextInt() != 0);
        System.out.println(sum);
    }

And What I get is as following:

Input: 3 6 8 0

Output:

11 <---it should come out as 17. Please figure out where the code is wrong.

Answer 1

Please try below code

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int sum = 0;
        int checker = 0;
        do {
            checker = scanner.nextInt();
            sum += checker;

        } while (checker != 0);
        System.out.println(sum);
    }
}

In your code value coming from scanner.nextInt() in while loop is being missed to be added. That's causing a issue

Answer 2

The problem with your code

public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int sum = 0;
    do {
        sum += scanner.nextInt(); // consuming an int from keyboard with nextInt()
    } while (scanner.nextInt() != 0); // consuming another int from keyboard with nextInt()
    System.out.println(sum);

for input 3 6 8 0

 sum += scanner.nextInt(); //this nextInt() consumes 3 now sum has 3
 scanner.nextInt() != 0 // this nextInt() consumes 6 but does not add to sum now sum has 3 only the 6 is ignored 

 sum += scanner.nextInt(); // same here this consumes 8 and add to sum now sum has 11 which is the output
 scanner.nextInt() != 0 // this nextInt() consumes 0 which fails the condition 

In short you are ignoring every second input

The fix

Scanner scanner = new Scanner(System.in);
         int sum = 0;
         int num = 0;
         while((num = scanner.nextInt()) != 0) { // nextInt() is called only once and value is cashed in num
             sum += num; // add this num to sum
         }
         System.out.println(sum); // prints 17 as expected

Answer 3

I am a beginner. I appreciate if someone solves my problem in simple way in Java.

Problem: Find the sum of all elements of a sequence, ending with the number 0. The number 0 itself is not included into the sequence and serves as a sign of cessation. Sample Input: 3 6 8 0 and Sample Output: 17

I am writing following program:

 import java.util.Scanner;
 class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int sum = 0;
        do {
            sum += scanner.nextInt();
        } while (scanner.nextInt() != 0);
        System.out.println(sum);
    }

And What I get is as following:

Input: 3 6 8 0

Output:

11 <---it should come out as 17. Please figure out where the code is wrong.