1. 概念
<< 左移運算符,左移是在后面補0, num << 1,相當于num乘以2
>> 右移運算符, 右移是在前面補1或0,num >> 1, 相當于num除以2
>>> 無符號右移,是在前面補0, 忽略符號位,空位都以0補齊
另外, 不論是左右還是右移32位,相當于不移動,還是原值。
實際上 在java虛擬機執行這句代碼的時候如下這樣執行的:
5>>(n%32)--->結果
你這里n=32 ;所以5>>32即是 5>>(32%32)-->5>>0 的結果;
2. 測試代碼
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public class test{ public test(){ system.out.println( "=============算術右移 >> ===========" ); int i= 0xc0000000 ; system.out.println( "移位前:i= " +i+ " = " +integer.tobinarystring(i)+ "(b)" ); i=i>> 28 ; system.out.println( "移位后:i= " +i+ " = " +integer.tobinarystring(i)+ "(b)" ); system.out.println( "---------------------------------" ); int j= 0x0c000000 ; system.out.println( "移位前:j= " +j+ " = " +integer.tobinarystring(j)+ "(b)" ); j=j>> 24 ; system.out.println( "移位后:j= " +j+ " = " +integer.tobinarystring(j)+ "(b)" ); system.out.println( "\n" ); system.out.println( "==============邏輯右移 >>> =============" ); int m= 0xc0000000 ; system.out.println( "移位前:m= " +m+ " = " +integer.tobinarystring(m)+ "(b)" ); m=m >>> 28 ; system.out.println( "移位后:m= " +m+ " = " +integer.tobinarystring(m)+ "(b)" ); system.out.println( "---------------------------------" ); int n= 0x0c000000 ; system.out.println( "移位前:n= " +n+ " = " +integer.tobinarystring(n)+ "(b)" ); n=n>> 24 ; system.out.println( "移位后:n= " +n+ " = " +integer.tobinarystring(n)+ "(b)" ); system.out.println( "\n" ); system.out.println( "==============移位符號的取模===============" ); int a= 0xcc000000 ; system.out.println( "移位前:a= " +a+ " = " +integer.tobinarystring(a)+ "(b)" ); system.out.println( "算術右移32:a=" +(a>> 32 )+ " = " +integer.tobinarystring(a>> 32 )+ "(b)" ); system.out.println( "邏輯右移32:a=" +(a>>> 32 )+ " = " +integer.tobinarystring(a>>> 32 )+ "(b)" ); system.out.println( "算術右移64:a=" +(a>> 64 )+ " = " +integer.tobinarystring(a>> 64 )+ "(b)" ); system.out.println( "邏輯右移64:a=" +(a>>> 64 )+ " = " +integer.tobinarystring(a>>> 64 )+ "(b)" ); } public static void main(string[] args){ new test(); } } |
運行結果:
=============算術右移 >> ===========
移位前:i= -1073741824 = 11000000000000000000000000000000(b)
移位后:i= -4 = 11111111111111111111111111111100(b)移位前:j= 201326592 = 1100000000000000000000000000(b)
移位后:j= 12 = 1100(b)==============邏輯右移 >>> =============
移位前:m= -1073741824 = 11000000000000000000000000000000(b)
移位后:m= 12 = 1100(b)移位前:n= 201326592 = 1100000000000000000000000000(b)
移位后:n= 12 = 1100(b)==============移位符號的取模===============
移位前:a= -872415232 = 11001100000000000000000000000000(b)
算術右移32:a=-872415232 = 11001100000000000000000000000000(b)
邏輯右移32:a=-872415232 = 11001100000000000000000000000000(b)
算術右移64:a=-872415232 = 11001100000000000000000000000000(b)
邏輯右移64:a=-872415232 = 11001100000000000000000000000000(b)
3. 為什么沒有無符號左移
這個問題大家可以思考一下,應該能想出來。(提示:沒有就是沒有存在的意思)
以上所述是小編給大家介紹的java中的移動位運算:,>>>詳解整合,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持!
原文鏈接:https://blog.csdn.net/weixin_34414196/article/details/87551511