Question

我是编码的新手，所以请耐心等待。在我的代码中，我在for循环中遇到了类型错误的非法启动（位于student类中）。我该如何解决这个错误？

在我的for循环中，我希望我的数组成绩有10个值（已定义），这些值将是60到99之间的随机值。在我看来，我认为这部分是正确的，并且在整个I中使用了正确的方法。所以，如果有人能看到我出错的地方，我将非常感激：）

import javax.swing.*;

public class StudentBase
{
  public static void main(String[] args){
      StudentBase app = new StudentBase();
      app.go();
    }

    void go(){
        //this is the main routine
         JOptionPane.showMessageDialog(null, "Welcome!" + '\n');

         String n = JOptionPane.showInputDialog("Type in your name");
         JOptionPane.showMessageDialog(null, "Press ok if your name is" + " " +  n);

         String h = JOptionPane.showInputDialog("What is your height? (in meters: eg - 1.80)");
         JOptionPane.showMessageDialog(null, "Press ok if your height is" + " " + h + " " + "meters");

         JOptionPane.showMessageDialog(null, "Introduction to student class:" + " " + "Hello! My name is" + " " + n + " " + "and I am" + " " + h + " " + "meters tall.");

         String students[] = new String [20];
         JOptionPane.showMessageDialog(null, students);
    }
}

//this is where Student Class is defined

class Student{
    //add variables, constructors and methods here
    String name = "";
    String height = "";
    int grades [] =new int [10];

  for(i = 0; i < grades.length; i++)
    {
        grades[i] = rand(60,99);
    }


    public Student(String n, String h, int g[])
    {
        name = n;
        height = h;
        grades = g;

    }

}

Answer 1

导致该特定错误的问题是，您尝试运行for循环而不将其作为任何方法或构造函数的一部分。你必须先包含它。此外，您需要在循环中声明i的类型，否则您也会遇到不同的错误。

class Student{
    //add variables, constructors and methods here
    String name = "";
    String height = "";
    int grades [] =new int [10];

    public void initGrades()
    {
        for(int i = 0; i < grades.length; i++)
        {
            grades[i] = rand(60,99);
        }
    }


    public Student(String n, String h, int g[])
    {
        name = n;
        height = h;
        grades = g;
        initGrades();
    }

}

我如何摆脱错误：在java中非法启动类型？

1 个答案: