java - 如何接受和输出数组中的 double 和整数？

Question

import java.util.Scanner;

public class PeopleWeights {

   public static void main(String[] args) {

     Scanner scnr = new Scanner(System.in);

     final int NUM_VALS = 5;

     int [] personsWeight = new int[NUM_VALS];

     int i = 0;

     for (i = 0; i < NUM_VALS; ++i) {
     System.out.print("Enter weight " + (i + 1) + ": ");
     System.out.println();
     personsWeight[i] = scnr.nextInt();
     }

     double sumVal = 0.0;

     for (i = 0; i < NUM_VALS; ++i) {
        sumVal = sumVal + personsWeight[i];
     }

     double avgVal = 0.0;

     for (i = 0; i < NUM_VALS; ++i) {
        avgVal = sumVal / NUM_VALS;
     }

     double maxVal = 0.0;

     for (i = 0; i < NUM_VALS; ++i) {
        maxVal = personsWeight[0];
        if (maxVal < personsWeight[i]) {
           maxVal = personsWeight[i];
        }
     }

     System.out.println();
     System.out.println(personsWeight[1] + " " + personsWeight[2] + " " 
     + personsWeight[3] + " " + personsWeight[4] + " " + personsWeight[5]);
//I know that this can be cleaner but this is where the 
//problem occurs with a InputMismatchException. 
//I know it's caused by the double being introduced 
//but don't know how to fix it.


     System.out.println("Total weight: " + sumVal);

     System.out.println("Average weight: " + avgVal);

     System.out.println("Max weight: " + maxVal);

     return;
  }
}

输入如下:
236,
89.5 ,
142,
166.3 ,
93 .

我想像输入一样处理输出数字。双倍或整数。

无论如何我可以让阵列在扫描仪中接受这两种类型的数字，还是我必须采用另一种工作方式？

Answer 1

您可以使用 hasNextInt() 初步确定输入的数字是 Double 还是 Integer或 hasNextDouble() Scanner的方法类(class)。

if (scnr.hasNextInt()) {
    int n = scnr.nextInt();
    //your code to handle `integer` case
}
else if(scnr.hasNextDouble()) {
    double d = scnr.nextDouble();
    //your code to handle `double` case
}

仅供引用，您也可以将所有内容保留为 double .它将同时处理 int s 和 double s 并将执行而不会出现任何错误。