为什么最后还要+three?
public class HelloWorld{
public static void main(String[] args) {
int one = 10 ;
int two = 20 ;
int three = 0 ;
three =one +two;
System.out.println("three =one +two==>"+three);
three += one ;
System.out.println("three += one ==>"+three);
three -= one;
System.out.println("three -=one ==>"+three);
three *= one;
System.out.println("three *=one ==>"+three);
three /=one;
System.out.println("three =one ==>"+three);