public class HelloWorld{

    public static void main(String[] args) {

    int one = 10 ;

        int two = 20 ;

        int three = 0 ;

        int three1 = one + two;

        System.out.println("three = one + two ==>" + three1);

        int three2 = three1 += one;

        System.out.println("three += one  ==>" + three2);

        int three3 = three2 -= one; 

        System.out.println("three -= one  ==>" + three3);

        int three4 = three1 *= one; 

        System.out.println("three *= one  ==>" + three4);

three4为什么显示的是400。three1 *=one应该是30*10=300啊。