对于这一小问~~我百思不得其解~~~郁闷了~~谁能指点迷津~~
class Number{
int i;
}

public class Assignment{
public static void main(String[] args){
Number n1=new Number();
Number n2=new Number();
n1.i=9;
n2.i=47;
System.out.println( "1:n1.i: "+n1.i+ ",n2.i: "+n2.i);
n1=n2;
System.out.println( "2:n1.i: "+n1.i+ ".,n2.i: "+n2.i);
n1.i=27;
System.out.println( "3:n1.i: "+n1.i+ ",n2.i: "+n2.i);
}
}

问：为什么我编译后，出现：Number.java:5: 类Assignment是公共的，应在名为Assignment.java的文件中声明public class Assignment{
^
1 错误

为什么呀~~~？？我明明public了呀，想不通了~~~~~？？

[解决办法]
把这个文件的名称改成Assignment.java
[解决办法]
每个类里面有切只能有一个public class类,