{"id":128,"date":"2014-08-18T15:05:34","date_gmt":"2014-08-18T07:05:34","guid":{"rendered":"https:\/\/yanjingang.com\/blog\/?p=128"},"modified":"2016-01-12T15:05:45","modified_gmt":"2016-01-12T07:05:45","slug":"php%e4%b8%ad%e7%9a%84%e4%ba%8c%e8%bf%9b%e5%88%b6%e4%bd%8d%e8%bf%90%e7%ae%97%e5%92%8c%e6%9d%83%e9%99%90%e5%ad%98%e5%82%a8","status":"publish","type":"post","link":"https:\/\/yanjingang.com\/blog\/?p=128","title":{"rendered":"PHP\u4e2d\u7684\u4e8c\u8fdb\u5236\u4f4d\u8fd0\u7b97\u548c\u6743\u9650\u5b58\u50a8"},"content":{"rendered":"
\u5728\u5f88\u591a\u7cfb\u7edf\u7684\u6743\u9650\/\u9009\u9879\u8bbe\u7f6e\u4e2d \u5f88\u591a\u90fd\u7528\u5230\u4e86\u4f4d\u8fd0\u7b97\u7684\u65b9\u6cd5\u6765\u5b58\u50a8\u591a\u79cd\u6807\u5fd7\u4f4d\u3002\u8fd9\u6837\u53ef\u4ee5\u8282\u7701\u5b57\u6bb5\u3002\u4e00\u4e2a\u5b57\u6bb5\u53ea\u9700\u8981\u4e00\u4e2a\u6570\u5b57 \u5c31\u53ef\u4ee5\u6807\u8bc6\u5f88\u591a\u79cd\u8bbe\u7f6e\u548c\u4fe1\u606f\u3002<\/div>\n

\u4e3e\u4f8b dicuz\u7684\u5e16\u5b50\u8868\u7684status\u5b57\u6bb5\uff0c\u5b98\u65b9\u9884\u7559\u4e8616\u4e2a\u6807\u5fd7\u4f4d(0x0000 – 0xFFFF) \u5373216<\/sup><\/p>\n

\u76ee\u524d\u89c4\u5212\u4f7f\u7528\u4e86\u53ea\u67098\u4e2a\u6807\u5fd7\u4f4d\uff0c\u5982\u4e0b<\/p>\n

\u00a00000 0000 0000 0001 \u662f\u5426\u7f13\u5b58\u5e16\u5b50\u4f4d\u7f6e\u4fe1\u606f
\n0000 0000 0000 0010 \u662f\u5426\u56de\u5e16\u53ea\u5bf9\u7ba1\u7406\u4eba\u5458\u548c\u53d1\u5e16\u8005\u53ef\u89c1
\n0000 0000 0000 0100 \u662f\u5426\u62a2\u697c\u8d34
\n0000 0000 0000 1000 \u662f\u5426\u5012\u5e8f\u67e5\u770b\u56de\u5e16
\n0000 0000 0001 0000 \u662f\u5426\u5b58\u5728\u4e3b\u9898\u56fe\u7ae0\u6807\u5fd7\u4f4d
\n0000 0000 0010 0000 \u56de\u590d\u662f\u5426\u901a\u77e5\u4f5c\u8005
\n0000 0000 0100 0000 \u662f\u5426\u63a8\u9001\u5230QQ\u7a7a\u95f4
\n0000 0000 1000 0000 \u662f\u5426\u63a8\u9001\u5230\u817e\u8baf\u5fae\u535a<\/p><\/blockquote>\n

\u8fd98\u79cd\u72b6\u6001\u53ef\u4ee5\u4f7f\u7528\u4e00\u4e2a\u6570\u5b57\u6765\u540c\u65f6\u8868\u793a\uff0c\u8282\u7701\u4e86\u5b57\u6bb5<\/p>\n

\u90a3\u4e48\u8fd9\u79cd\u4e1c\u897f\u7684\u539f\u7406\u662f\u4ec0\u4e48\u5462<\/p>\n

\u8fd9\u4e2a\u6211\u4eec\u53ef\u4ee5\u590d\u4e60\u4e00\u4e0b\u7684\u4f4d\u8fd0\u7b97\u5355\u7b97\u6cd5<\/p>\n\n\n\n\n\n\n\n\n\n\n
\u4f8b\u5b50<\/th>\n\u540d\u79f0<\/th>\n\u7ed3\u679c<\/th>\n<\/tr>\n<\/thead>\n
$a & $b<\/td>\nAnd\uff08\u6309\u4f4d\u4e0e\uff09<\/td>\n\u5c06\u628a $a \u548c $b \u4e2d\u90fd\u4e3a 1 \u7684\u4f4d\u8bbe\u4e3a 1\u3002<\/td>\n<\/tr>\n
$a | $b<\/td>\nOr\uff08\u6309\u4f4d\u6216\uff09<\/td>\n\u5c06\u628a $a \u6216\u8005 $b \u4e2d\u4e3a 1 \u7684\u4f4d\u8bbe\u4e3a 1\u3002<\/td>\n<\/tr>\n
$a ^ $b<\/td>\nXor\uff08\u6309\u4f4d\u5f02\u6216\uff09<\/td>\n\u5c06\u628a $a \u548c $b \u4e2d\u4e0d\u540c\u7684\u4f4d\u8bbe\u4e3a 1\u3002<\/td>\n<\/tr>\n
~ $a<\/td>\nNot\uff08\u6309\u4f4d\u975e\uff09<\/td>\n\u5c06 $a \u4e2d\u4e3a 0 \u7684\u4f4d\u8bbe\u4e3a 1\uff0c\u53cd\u4e4b\u4ea6\u7136\u3002<\/td>\n<\/tr>\n
$a << $b<\/td>\nShift left\uff08\u5de6\u79fb\uff09<\/td>\n\u5c06 $a \u4e2d\u7684\u4f4d\u5411\u5de6\u79fb\u52a8 $b \u6b21\uff08\u6bcf\u4e00\u6b21\u79fb\u52a8\u90fd\u8868\u793a\u201c\u4e58\u4ee5 2\u201d\uff09\u3002<\/td>\n<\/tr>\n
$a >> $b<\/td>\nShift right\uff08\u53f3\u79fb\uff09<\/td>\n\u5c06 $a \u4e2d\u7684\u4f4d\u5411\u53f3\u79fb\u52a8 $b \u6b21\uff08\u6bcf\u4e00\u6b21\u79fb\u52a8\u90fd\u8868\u793a\u201c\u9664\u4ee5 2\u201d\uff09\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u6bd4\u5982<\/p>\n

\u4e0e\u8fd0\u7b97<\/h1>\n

14 = 0b1110<\/p>\n

11 = 0b1011<\/p>\n

\u90a3\u4e48 14 & 11\u00a0 = 0b1110 & 0b1011 = 0b1010 = 10<\/p>\n

\u6216\u8fd0\u7b97<\/h1>\n

\u8fd8\u662f\u4e0a\u9762\u90a3\u4e2a\u4f8b\u5b50<\/p>\n

14 | 11 = 0b1110 | 0b1011 = 0b1111 = 15<\/p>\n

\u5f02\u6216\u8fd0\u7b97<\/h1>\n

14 ^ 11 = 0b1110 ^ 0b1011 = 0b0101 = 5<\/p>\n

\u975e\u8fd0\u7b97<\/h1>\n

\u975e\u8fd0\u7b97\u6bd4\u8f83\u7279\u6b8a \u6d89\u53ca\u5230\u7b26\u53f7 \u8fd9\u91cc\u8981\u8bf4\u4e00\u4e0b\u8865\u7801 \u53cd\u7801 \u539f\u7801\u7684\u6982\u5ff5<\/p>\n

1.\u4e8c\u8fdb\u5236\u6700\u9ad8\u662f\u7b26\u53f7\u4f4d\u00a0 0\u662f\u6b63\u6570\u00a0 1\u8868\u793a\u8d1f\u6570<\/p>\n

2.\u6b63\u6570\u7684 \u539f\u7801 \u53cd\u7801\u00a0 \u8865\u7801 \u90fd\u4e00\u6837\uff08\u6211\u4e0a\u9762\u6ca1\u6709\u5355\u72ec\u7b97\u8865\u7801\u7684\u539f\u56e0 \uff0c\u6b63\u6570\u8865\u7801\u548c\u53cd\u7801\u4e00\u6837\uff09<\/p>\n

3.\u7528\u4e8c\u8fdb\u5236\u8868\u793a\u4e00\u4e2a\u6570\u00a0 \u8fd9\u4e2a\u7801 \u5c31\u662f\u539f\u7801 \u6bd4\u5982 14\u7684\u539f\u7801\u5c31\u662f 1110<\/p>\n

4.\u8d1f\u6570\u7684\u53cd\u7801 \u7b49\u4e8e\u00a0 \u4ed6\u7b26\u53f7\u4f4d\u4e0d\u53d8 \u5176\u4ed6\u53d6\u53cd\uff0c\u800c\u8d1f\u6570\u7684\u8865\u7801\u7b49\u4e8e\u4ed6\u7684\u53cd\u7801+1<\/p>\n

5.\u8ba1\u7b97\u673a\u8fd0\u7b97\u7684\u65f6\u5019 \u5168\u90fd\u662f\u4ee5\u8865\u7801\u7684\u5f62\u5f0f\u6765\u8fd0\u7b97\u7684 \u4e0d\u7ba1\u6b63\u8d1f\u6570<\/p><\/blockquote>\n

\u90a3\u4e48<\/p>\n

1 \u662f\u6b63\u6570\uff0c\u90a3\u4e48\u4ed6\u7684\u539f\u7801 0001 = \u53cd\u7801 = \u8865\u7801 = 0001 =>\u53d6\u53cd \u540e\u8865\u78011110 <=\u53cd\u7801 1101<=\u539f\u78011010<\/p>\n

\u90a3\u4e48\u8fd9\u4e2a\u7b26\u53f7\u4f4d\u662f1\u5c31\u662f\u8d1f\u6570 \u4e5f\u5c31\u662f010\u4ee3\u8868\u7684\u8d1f\u6570\u5c31\u662f-2 \u4e5f\u5c31\u662f \uff5e1 = -2<\/p>\n

\u00a0\u5de6\u53f3\u4f4d\u79fb\u8fd0\u7b97<\/h1>\n

1<< 2
\n1\u7684\u8865\u7801\u00a0\u00a0\u00a0 00000001
\n\u79fb\u52a82\u4f4d\u00a0\u00a0\u00a0 00000100
\n\u6b63\u6570\u7684\u53cd\u7801 \u8865\u7801\u00a0 \u539f\u7801 \u90fd\u4e00\u6837 \u6240\u4ee5 \u662f\u4e2a4<\/p>\n

\u8d1f\u6570\u7684\u8ba1\u7b97\u8fc7\u7a0b\u76f8\u540c \u4e0d\u518d\u8d58\u8ff0 \u5de6\u79fb\u4e5f\u7c7b\u4f3c 4>>2\u00a0 \u5c31\u662f1<\/p>\n

\u5176\u5b9e\u53ef\u4ee5\u7406\u89e3\u4e3a\u53f3\u79fb\u5728\u5341\u8fdb\u5236\u7684\u8868\u73b0\u4e0a\u5c31\u662f\u4e58\u4ee52 \u5de6\u79fb \u5728\u5341\u8fdb\u5236\u7684\u8868\u73b0\u4e0a\u5c31\u662f\u9664\u4ee52<\/p>\n

\n

\u90a3\u4e48\u56de\u5230\u672c\u6587\u6b63\u9898 \u5982\u4f55\u7528\u4e00\u4e2a\u6570\u5b57\u6765\u6807\u8bc6\u8fd9\u4e9b\u6743\u9650\u4f4d\u5462\uff1f<\/p>\n

\u4ee5\u521a\u624ddiscuz\u7684\u5e16\u5b50\u8868\u8fbestatus\u5b57\u6bb5\u4e3a\u4f8b\uff0c\u68c0\u67e5\u5e16\u5b50\u56de\u590d\u662f\u5426\u901a\u77e5\u4f5c\u8005 \u5c31\u770b\u4e8c\u8fdb\u5236\u4e0a\u7b2c\u516d\u4f4d\u662f\u5426\u662f\u7f6e\u4f4d\u4e3a1 \u90a3\u4e48\u600e\u4e48\u68c0\u67e5\u5462\uff1f\u5c31\u662f\u7528\u4e0a\u9762\u6211\u4eec\u63d0\u5230\u7684\u4e0e\u8fd0\u7b97\u3002<\/p>\n

\u4e0e\u8fd0\u7b97\u662f\u5c06\u628a $a \u548c $b \u4e2d\u90fd\u4e3a 1 \u7684\u4f4d\u8bbe\u4e3a 1\u3002\u90a3\u4e48\u5047\u8bbe<\/p>\n

$a=36=0b 0010 0100<\/p>\n

$b=0b 0010 0000<\/p>\n

$a&$b = 0b 0010 0100 & 0b 0010 0000 = 0b 0010 0000 = 32 = 26-1<\/sup>\u00a0= 25<\/sup><\/p>\n

\u56e0\u6b64 \u68c0\u67e5\uff0c\u67d0\u4e2a\u6570\u4ee3\u8868\u7684\u7b2cN\u4e2a\u6743\u9650\u6807\u5fd7\u4f4d\u6709\u6ca1\u6709\u7f6e\u4f4d\uff08\u662f1\uff09 \u53ea\u8981\u9009\u62e9\u8be5\u6570\u4e0e\u4ec5\u8be5\u6807\u5fd7\u4f4d\u7f6e\u4f4d\u7684\u64cd\u4f5c\u65702N-1<\/sup>\u8fdb\u884c\u4e0e\u8fd0\u7b97\u5373\u53ef\uff0c\u76f8\u53cd\u8981\u8ba1\u7b97\u67d0\u4e2a\u6807\u5fd7\u4f4d\u88ab\u7f6e\u4f4d\u7684\u6570\u5b57 \u53ea\u8981\u9009\u62e9\u5408\u9002\u7684\u64cd\u4f5c\u6570\u8fdb\u884c\u6216\u8fd0\u7b97\u5373\u53ef\u3002\u6211\u4eec\u53ef\u4ee5\u770bdiscuz\u5bf9\u6b64\u7684\u5b9e\u73b0\uff1a<\/p>\n

function getstatus($status, $position) { $t = $status & pow(2, $position – 1) ? 1 : 0; return $t;}function setstatus($position, $value, $baseon = null) { $t = pow(2,$position – 1); if($value) { $t = $baseon | $t; } elseif ($baseon !== null) { $t = $baseon & ~$t; } else { $t = ~$t; } return $t & 0xFFFF;}<\/p>\n

\u6ce8\u610f \u5199\u8fd9\u6bb5\u4ee3\u7801\u7684\u4eba\u663e\u7136\u53d7\u5230\u4e86C\u7684\u5f71\u54cd \u5176\u5b9e $a & ~$b \u548c $a ^ $b \u662f\u7b49\u6548\u7684 \u53ea\u4e0d\u8fc7 ^\u662fPHP\u7684\u5199\u6cd5 \u53e6\u5916 pow(2, $position – 1)\u6362\u6210 1 << ($position -1) \u5176\u5b9e\u66f4\u597d\u7406\u89e3\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5728\u5f88\u591a\u7cfb\u7edf\u7684\u6743\u9650\/\u9009\u9879\u8bbe\u7f6e\u4e2d \u5f88\u591a\u90fd\u7528\u5230\u4e86\u4f4d\u8fd0\u7b97\u7684\u65b9\u6cd5\u6765\u5b58\u50a8\u591a\u79cd\u6807\u5fd7\u4f4d\u3002\u8fd9\u6837\u53ef\u4ee5\u8282\u7701\u5b57\u6bb5\u3002\u4e00\u4e2a\u5b57\u6bb5\u53ea\u9700\u8981\u4e00\u4e2a\u6570 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[5,109],"_links":{"self":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/128"}],"collection":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=128"}],"version-history":[{"count":0,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/128\/revisions"}],"wp:attachment":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=128"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}