{"id":207405,"date":"2020-11-26T10:14:37","date_gmt":"2020-11-26T02:14:37","guid":{"rendered":"http:\/\/4563.org\/?p=207405"},"modified":"2020-11-26T10:14:37","modified_gmt":"2020-11-26T02:14:37","slug":"%e8%bf%99%e4%b8%aa%e6%b5%ae%e7%82%b9%e6%95%b0%e5%8a%a0%e6%b3%95%e7%ae%97%e6%b3%95%e7%a9%b6%e7%ab%9f%e5%93%aa%e9%87%8c%e4%b8%8d%e5%af%b9%ef%bc%9f","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=207405","title":{"rendered":"\u8fd9\u4e2a\u6d6e\u70b9\u6570\u52a0\u6cd5\u7b97\u6cd5\u7a76\u7adf\u54ea\u91cc\u4e0d\u5bf9\uff1f"},"content":{"rendered":"
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\u8fd9\u4e2a\u6d6e\u70b9\u6570\u52a0\u6cd5\u7b97\u6cd5\u7a76\u7adf\u54ea\u91cc\u4e0d\u5bf9\uff1f <\/h1>\n

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\u8cc7\u6df1\u5927\u4f6c : rcocco <\/span> <\/i> 1<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u8ba1\u7b971000.1+0.2<\/code>\uff0c\u628a\u5c3e\u6570\u524d\u9762\u9690\u542b\u7684 1 \u4f4d\u4e5f\u5199\u51fa\u6765\uff0c\u4e5f\u52a0\u4e0a Guard bit \u3001Round bit \u548c Sticky bit<\/p>\n

1000.1 = 0 10000001000 1.1111010000001100110011001100110011001100110011001101 000  0.2 = 0 01111111100 1.1001100110011001100110011001100110011001100110011010 000 <\/code><\/pre>\n
    \n
  1. \u6307\u6570\u5927\u7684\u51cf\u5c0f\u7684\u5f97\u5230\u79fb\u4f4d\u91cf10000001000-01111111100=1100<\/code>\uff0c\u5373 12 \u3002<\/li>\n
  2. \u628a\u8f83\u5c0f\u503c\u7684\u5c3e\u6570\u53f3\u79fb 12 \u4f4d\u5f97\u5230\n
    0.0000000000011001100110011001100110011001100110011001 100 <\/code><\/pre>\n<\/li>\n
  3. \u5c3e\u6570\u76f8\u52a0\n
    1.1111010000001100110011001100110011001100110011001101 000 + 0.0000000000011001100110011001100110011001100110011001 100 ========================================================== 1.1111010000100110011001100110011001100110011001100110 100 <\/code><\/pre>\n<\/li>\n
  4. \u9690\u542b\u4f4d\u4e3a 1\uff0c\u4e0d\u9700\u8981\u518d\u8c03\u6574\uff0c\u5f97\u5230\n
    0 10000001000 1.1111010000100110011001100110011001100110011001100110 100 <\/code><\/pre>\n<\/li>\n
  5. Guard bit \u3001Round bit \u548c Sticky bit \u662f100<\/code>\u4e2d\u95f4\u503c\uff0c\u5411\u5076\u6570\u820d\u5165\uff0c\u4f7f\u6700\u4f4e\u6709\u6548\u4f4d\u4e3a 0\n
    0 10000001000   1111010000100110011001100110011001100110011001100110 <\/code><\/pre>\n<\/li>\n<\/ol>\n
    \u4e3a\u5565\u8fd9\u6837\u7b97\u51fa\u6765\u7684\u503c\u548c JavaScript \u4e2d1000.1+0.2<\/code>\u5dee 1 \u4e2a bit \uff1f JS \u4e2d\u5f97\u5230\u7684\u503c\u662f\u4e0b\u9762\u8fd9\u4e2a<\/p>\n
    0 10000001000 1111010000100110011001100110011001100110011001100111 <\/code><\/pre>\n
    \u548c\u4e4b\u524d\u7b97\u7684\u5c31\u5dee 1 \u4e2a bit<\/p>\n
    0 10000001000 1111010000100110011001100110011001100110011001100110 <\/code><\/pre>\n
    let d = new DataView(new ArrayBuffer(8)); d.setFloat64(0, 1000.1+0.2); console.log(d.getBigUint64(0).toString(16)); <\/code><\/pre>\n<\/p><\/div>\n
     \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (2<\/span>)        <\/div>\n
     <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
      \n
    • \n
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       \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span>  <\/div>\n
       <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                   \u731c\u60f3\u662f\u53f3\u79fb 12 \u4f4d\u540e\u6700\u540e 1001 101 \u5427\uff1f
      \u90a3\u6837\u5c31\u8fdb\u4e86 1                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
    • \n
      \n
      \n
       \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : rcocco <\/span>  <\/div>\n
       <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                   @no1xsyzy \u5bf9\uff0c\u6211\u5fd8\u4e86 sticky bit \u7f6e 1 \u540e\u54ea\u6015\u518d\u79fb\u4f4d\u4e5f\u662f\u4e0d\u53d8\u7684\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
    • \n","protected":false},"excerpt":{"rendered":"
      \u8fd9\u4e2a\u6d6e\u70b9\u6570\u52a0\u6cd5\u7b97\u6cd5\u7a76\u7adf\u54ea\u91cc\u4e0d\u5bf9\uff1f …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/207405"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=207405"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/207405\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=207405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=207405"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=207405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}