Question

该代码应该询问事故的数量，并确定五个地区中哪个事故发生率最低，并打印事故数量和地区。我对java很新，我遇到了这个错误。它说第四类Homework中的方法getNumAccidents不能应用于给定的类型; required：double found：无参数原因：实际和正式列表的长度不同。我该如何解决这个问题？

import java.util.*;
public class fourthHomework
{
public static void main(String args[]) {
double smallest = 0;
double north = getNumAccidents();
double south = getNumAccidents();
double east = getNumAccidents();
double west = getNumAccidents();
double central = getNumAccidents();

getNumAccidents(smallest);
findLowest(north, south, east, west, central, smallest);


}
public static double getNumAccidents(double smallest) {
System.out.println("Please enter all accidents as positive numbers.");
Scanner input = new Scanner(System.in);
System.out.print("Please enter the amount of accidents: ");
smallest = input.nextDouble();
}

public static void findLowest(double north, double south, double east, double west, double central, double smallest) {
System.out.println("The lowest amount of accidents this year was " +smallest);
if (north == smallest)
{
    System.out.println("The region that had the least amount of accidents was the north.");
}

if (south == smallest)
{
    System.out.println("The region that had the least amount of accidents was the south.");
}

if (east == smallest)
{
    System.out.println("The region that had the least amount of accidents was the east.");
}

if (west == smallest)
{
    System.out.println("The region that had the least amount of accidents was the west.");
}

if (central == smallest)
{
    System.out.println("The region that had the least amount of accidents was the central region.");
}

} }

Answer 1

您的问题是因为在您的方法getNumAccidents（最小的双倍）中，您需要double作为参数。如果您声明北，南，东，西和中央的双打，则不要为该方法添加任何参数。你需要添加双打，否则它会运行。此外，既然你说该方法会返回一个double，你需要在方法的最后说

return smallest

Answer 2

让主方法的开头显示：

public static void main(String args[]) {
    double smallest = 0.0;
    double north = getNumAccidents(smallest);
    double south = getNumAccidents(smallest);
    double east = getNumAccidents(smallest);
    double west = getNumAccidents(smallest);
    double central = getNumAccidents(smallest);
...

在你的getNumAccidents方法中，由于它被声明为double，你需要返回一个double值：

...
smallest = input.nextDouble();
return smallest;
}

这不会完全修复该程序，但它可以帮助您解决问题。

错误，方法不能应用于给定的类型

2 个答案: