移位操作符 << >> >>>

按位操作符只可用于int类型,其它类型都会转化位int类型在操作,并且只有数值右端的低5位才右用(因为2^5=32)

<<  左移位操作符,低位补零

>>  右移位操作符,有符号数高位补1,无符号数高位补0

>>  java专用右移位操作符;无任正负,都在高位插入0(linux 下负数用>>>在高位补1)

//: object/Shifting.java

package object;
import java.util.*;
import static net.util.Print.*;

public class Shifting{
    public static void main(String[] args){
        int n1 =-4;
        print("n1<<2 = "+Integer.toBinaryString(n1<<2));
        print("n1<<2 = "+Integer.toBinaryString(n1>>2));
        print("n1<<2 = "+Integer.toBinaryString(n1>>>2));
        print("n1<<2 = "+(n1>>>2));
    }
}/* output:
n1<<2 = 11111111111111111111111111110000
n1<<2 = 11111111111111111111111111111111
n1<<2 = 111111111111111111111111111111
n1<<2 = 1073741823
*///~