helloworld在编译的时候出现这样的错误是为什么，大家指点，3x

Question

public class HelloWorld{...}

Answer 1

class helloWorld{
    public static void main(Stirng [] s){
        JOptionPane.showMessageDialog(null, 
                                      "Hello World!",
                                      "Alert",  
                                      JOptionPane.INFORMATION_MESSAGE);
    } 
}

Answer 2

根据这个继续出现这样的错误：hello.java:6: cannot resolve symbol
symbol  : variable JOptionPane
location: class helloWorld
                                      JOptionPane.INFORMATION_MESSAGE);
                                      ^
hello.java:3: cannot resolve symbol
symbol  : variable JOptionPane
location: class helloWorld
        JOptionPane.showMessageDialog(null,
        ^
2 errors

Answer 3

上面那个代码你要导入Swing包的，要不怎么可能有那个类

Answer 4

文件头加句 import javax.swing.*;

Answer 5

import javax.swing.*;public class helloWorld{
    public static void main(Stirng [] s){
        JOptionPane.showMessageDialog(null, 
                                      "Hello World!",
                                      "Alert",  
                                      JOptionPane.INFORMATION_MESSAGE);
    } 
}

Answer 6

helloWorld.java
import javax.swing.*;public class helloWorld{
    public static void main ( String args[] ) {
        JOptionPane.showMessageDialog(null, 
                                      "Hello World!",
                                      "Alert",  
                                      JOptionPane.INFORMATION_MESSAGE);
    } 
}
完整的是这样吧，但是还是出现同样的错误

Answer 7

你的JAVA_HOME怎么设的？我想可能是classpath的问题。

Answer 8

那就不要图形界面了helloWorld.java
//import javax.swing.*;public class helloWorld{
    public static void main ( String args[] ) {
        System.out.println("hello world！");    } 
}

Answer 9

这个程序不需要设置classpath 的吧！