java - 如何将 int 转换为 double？

Question

该程序的目的是从用户处获取 5 个值(测试分数)，然后输出平均分数。我对数组不熟悉，所以我真的不知道我做错了什么。我所知道的是双“sum”不能设置为等于int“total”。抱歉我很蠢，但我正在尝试:)

import java.util.Scanner;

public class Main
{

  public static void main (String [] args)
  {

    int x = 0;
    double testScore[] = new double[5];
    double sum[] = new double[5];
    double total;
    int avg;

    Scanner keys = new Scanner(System.in);

    System.out.println("Enter the values of 5 separate test scores that you have received: \n");

    for (int i = 0; i < testScore.length; i++)
    {
        x++;
        System.out.println("Enter your grade for test number " +1);
        double score = keys.nextDouble();

        score = testScore[i];
        sum = testScore;
        sum = (int)total;
        avg = ((total) / 5);


        System.out.print("The sum of your grades is " +avg +"\n");
    }

  }
}

Answer 1

double sum = 0;
for (double score: testScore) {
  sum += score;
}
double avg = sum / testScore.length;