java - 如何将对话框中用户输入的数据值存储到数组中？

Question

import javax.swing.JOptionPane;
import java.text.DecimalFormat;

public class quiz
  public static void main(String[] args)
  {
    String name, allname, loopname;
    int names, allnames, op, loopsname;
    int arValues[];

    name = JOptionPane.showInputDialog(null, "Enter how many friends you have:");
    names = Integer.parseInt(name);
    arValues = new int[name-1];

**for(names = 0; names == names; names++)
{
  loopname = JOptionPane.showInputDialog(null, "enter your friend's names);
  loopsname = Integer.parseInt(loopsname);
  arValues[names] = loopsname;
}**

allname = JOptionPane.showInputDialog(null, "Enter the number of which friends name in which you want to see");
allnames = Integer.parseInt(allname);
op = arValues[allnames];

}

 public static void finish()
{
  System.exit(0);
}
}

代码可以编译，但运行时会出现多个运行时错误，包括越界。需要帮助解决这个问题

错误消息:

java.lang.ArrayIndexOutOfBoundsException: 2 at quiz.main(quiz.java:28) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:27‌​2)

Answer 1

在 for 循环中，条件 names == names 始终为 true。你应该做的是使用一个临时变量，比如说i，如下所示:

for (int i = 0; i < names; i++) {
    loopname = JOptionPane.showInputDialog(null, "Enter value for array:");
    loopsnames = Integer.parseInt(loopsnames);
    arValues[i] = loopsnames;
}

循环的每次迭代现在都会检查 i 以查看它是否小于 names，如果是，则递增它并运行循环内的代码。这可确保循环精确运行 values 次。导致错误的另一个地方是该行:

arValues = new int[names-1];

你应该这样做:

arValues = new int[names];

因为您想准确保留 names 元素。
这是代码的完整且有效的版本:

import javax.swing.JOptionPane;
import java.text.DecimalFormat;

public class  quiz {
    public static void main(String[] args) {
        String name, allname, loopname;
        int names, allnames, op, loopsname;
        int arValues[];

        name = JOptionPane.showInputDialog(null, "Enter how many friends names you would like ot enter");
        names = Integer.parseInt(name);
        arValues = new int[value];

        for (int i = 0; i < names; i++) {
            loopname = JOptionPane.showInputDialog(null, "Enter your friend's name");
            loopnames = Integer.parseInt(loopname);
            arValues[i] = loopnames;
        }

        allname = JOptionPane.showInputDialog(null, "Enter the number of which friend you want to see");
        allnames = Integer.parseInt(allname);
        op = arValues[allnames];
    }

    public static void finish() {
        System.exit(0);
    }
}