Question

如何在java中找出十进制数字的总和。我已经尝试了像对待int值一样的常规方法，但是总和仅在精度数字之前和在精度数字之后才不清楚输出。搜索但没有答案。

public static void main(String[] args) {

        double rem;
        double sum = 0.0;

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a 5 digit decimal number:");

        double num = sc.nextDouble();

        while(num > 0) {

            rem = num % 10;
            sum = sum + rem;
            num = num / 10;

        }
        System.out.println("Sum of digits = "+sum);
    }

预期输出：

输入数字：12.12

总和：6.0

我得到的输出：

输入数字：12.12

总和：3.4666666666666655

感谢您的帮助。

Answer 1

一一检查数字并将它们加到总和上。试试这个，

int sum = 0;

Scanner sc = new Scanner(System.in);
System.out.println("Enter a 5 digit decimal number:");

char[] s = sc.next().toCharArray();

for (int i = 0; i < s.length; i++) {
    try {
        sum += Integer.parseInt(s[i] + "");
    } catch (Exception e) {
    }
}

System.out.println("Sum of digits = " + sum);

Answer 2

如果您不想使用异常处理，则应尝试此操作-

public static void main(String[] args) {
 double sum = 0.0;
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter a 5 digit decimal number:");
        double num = sc.nextDouble();

        String number = String.valueOf(num);
        for (char c : number.toCharArray()) {
                if(c!='.')
                    sum += Integer.parseInt(String.valueOf(c));

        }
        System.out.println("Sum of digits = " + sum);
}

Answer 3

这是在Java 8+中完成此操作的简单方法（注释中的解释）：

class Main{
  public static void main(String[] a){
    java.util.Scanner scanner = new java.util.Scanner(System.in);
    String input = scanner.nextLine();               // Get the input-decimal as String
    int sumOfDigits = input.replaceAll("[^0-9]", "") // Remove all non-digits from the input-String
                           .chars()                  // Convert it to a stream of characters
                           .map(c -> c-48)           // Convert the character to a digit
                           .sum();                   // Sum everything together
    System.out.println("Sum of digits = "+sumOfDigits);
  }
}

Try it online.

Answer 4

public static void main(String[] args) {

    double sum = 0.0;
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter a 5 digit decimal number:");
    double num = sc.nextDouble();

    String number = String.valueOf(num);
    for (char c : number.toCharArray()) {
        try {
            sum += Integer.parseInt(String.valueOf(c));
        } catch (NumberFormatException e) {
            // ignore the . 
        }
    }
    System.out.println("Sum of digits = " + sum);
}

Java

4 个答案: