java - 如何解决 NumberFormatException : Empty string?

Question

当我运行这个程序时，我在线程“main”java.lang.NumberFormatException 中收到错误异常:空字符串。是否可以通过某种方式或必须使用 try catch 语句抛出异常来完成这项工作？

private double[] scores3 = new double[5]; 
Scanner keyboard = new Scanner(System.in);

public void enterData() 
{
   double score;
   double numberMin = 0;
   double numberMax = 100;



do{
    System.out.println("Enter the student's third test score");

      while (!keyboard.hasNextDouble()) {

      keyboard.next();
      }
       score3 = keyboard.nextDouble();


        }
         while  (score3 <= numberMin || score3 >= numberMax);
         double score3 = Double.parseDouble(keyboard.nextLine());

Answer 1

在将字符串解析为数字之前.. 将字符串与 ""进行比较或使用 isEmpty() 函数来检查它是否为空字符串!

例子:

if (myString.isEmpty()) {
    //Do Nothing
} else {
    //Code to perform calculations
}

或

if (!myString.isEmpty()) {
    //Code to perform calculations
}