小编Rou*_*bie的帖子

编译完代码后,我遇到了两个错误.

错误是:

1.

  local variable input is accessed within inner class; 
  needs to be declared final
     String name = input.getText();

2.

  local variable c_age is accessed within inner class; 
  needs to be declared final
     Object child_age = c_age.getSelectedItem();

这是我的代码:

import javax.swing.*;
import java.awt.event.*;

public class GUI
{
    public static void main(String[] args)
    {
        JFrame frame = new JFrame("Try GUI");
        JLabel l1 = new JLabel("Please Enter Your Child's Name");
        JTextField input = new JTextField("",10);

        JLabel l2 = new JLabel("Choose Your Child's …

我正在尝试在文件中声明一个包,如下所示:

import java.util.*;

package rtg;

public class Generate
{
    // ...
}

但是当我尝试编译时遇到错误:

Generate.java:3: class, interface, or enum expected package rtg;

为什么我收到此错误？

我有这个代码:

static ArrayList<Integer> output_list = new ArrayList<Integer>();
static ArrayList<Integer> pair_list = new ArrayList<Integer>();

    for (Iterator it=output_list.iterator(); it.hasNext();)
        {
            int pair_test = (int)output_list.next();
            for (int i=0; i<pair_list.length; i++)
            {

                if(!pair_list[i]==0)
                {
                    if (pair_list[i]==pair_test[i])
                    {
                        boolean check;
                        check=true;
                    }
                }
            }
        }

但我在编译时遇到了"无法找到符号"的错误.

symbol  : variable length
location: class java.util.ArrayList<java.lang.Integer>
                        for (int i=0; i<pair_list.length; i++)
                                                 ^
Prior.java:79: array required, but java.util.ArrayList<java.lang.Integer> found
                                if(!pair_list[i]==0)
                                             ^
Prior.java:79: incomparable types: boolean and int
                                if(!pair_list[i]==0)
                                                ^
Prior.java:81: array required, but java.util.ArrayList<java.lang.Integer> found
                                        if (pair_list[i]==pair_test[i])
                                                     ^
Prior.java:81: …