为什么第七行加个int 声明,代码就报错
public class HelloWorld{
public static void main(String[] args) {
int one = 10 ;
int two = 20 ;
int three = one + two ;
System.out.println(""+three);
int three += one;
System.out.println(""+three);
three -= one;
System.out.println(""+three);
three *= one;
System.out.println(""+three);
three /= one;
System.out.println(""+three);
three %= one;
System.out.println(""+three);