尝试创建双变量类型的数组时出错

Question

我正在尝试创建一个程序，该程序从用户那里获取双精度值并将它们存储在数组中，然后再对它们进行除法和四舍五入。但是，我在尝试创建双数组时不断收到错误消息。

 double n = sc.nextDouble();

    double a[] = new double[n];
    double b[] = new double[n];
    double roundedValues[] = new double[n];

    for (double i = 0; i < a.length; i++) {
        System.out.println("Please enter the values you would like to divide as pairs of two numbers: ");
        // Read pair and store it inside i-th position of a and b arrays 
        System.out.println("Enter first number: ");
        a[i] = sc.nextDouble();
        System.out.println("Enter second number you would like to divide by: ");
        b[i] = sc.nextDouble();
        roundedValues[i] = Math.round(a[i] / b[i]);
    }

我在声明数组的地方遇到的错误是：

不兼容的类型：从 double 到 int 的可能有损转换

Answer 1

首先，变量n，定义为double n = sc.nextDouble();是一个double。你不能创建一个长度为双精度的数组，因为那样你可能会得到半个元素。想象一个 4.5 个元素长的数组！

将n 定义为以下之一：

int n = sc.nextInt()
或
int n = (int)sc.nextDouble();

其次，i也是一个double！像这样定义它：

for (int i = 0; i < a.length; i++) {

这样编译器就知道i 是一个整数，并且不必担心需要检索double 索引处的元素，比如第4.2 个元素！ （不存在也不应该存在）

这是固定代码：
int n = sc.nextInt();

double a[] = new double[n];
double b[] = new double[n];
double roundedValues[] = new double[n];

for (int i = 0; i < a.length; i++) {
    System.out.println("Please enter the values you would like to divide as pairs of two numbers: ");
    // Read pair and store it inside i-th position of a and b arrays 
    System.out.println("Enter first number: ");
    a[i] = sc.nextDouble();
    System.out.println("Enter second number you would like to divide by: ");
    b[i] = sc.nextDouble();
    roundedValues[i] = Math.round(a[i] / b[i]);
}

Answer 2

a[i] and b[i] expect int type, but you supply double to it
Should be 
 for (int i = 0; i < a.length; i++) {

和

 double n = sc.nextDouble();
   should be changed to:
 int n = sc.nextInt();