java - 如何消除错误 : illegal start of type in java?

Question

我是编码新手，所以请耐心等待。在我的代码中，我在 for 循环(位于学生类(class)中)中遇到非法开始类型错误。我该如何修复这个错误？

在我的 for 循环中，我想让我的数组 Grades 有 10 个值(已经定义)，这些值将从 60 到 99 随机。在我看来，我认为这部分是正确的，并且自始至终我都使用了正确的方法。因此，如果有人能看到我哪里出了问题，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，但它不属于任何方法或构造函数。你必须首先涵盖它。另外，您需要在循环中声明 i 的类型，否则您也会收到不同的错误。

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();
    }

}