{"id":127262,"date":"2020-06-05T11:05:05","date_gmt":"2020-06-05T03:05:05","guid":{"rendered":"http:\/\/4563.org\/?p=127262"},"modified":"2020-06-05T11:05:05","modified_gmt":"2020-06-05T03:05:05","slug":"cnull-%e6%a3%80%e6%9f%a5%e8%bf%90%e7%ae%97%e7%ac%a6%ef%bc%88-%ef%bc%89%e5%92%8c%e6%b3%9b%e5%9e%8b","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=127262","title":{"rendered":"C#NULL \u68c0\u67e5\u8fd0\u7b97\u7b26\uff08?.\uff09\u548c\u6cdb\u578b"},"content":{"rendered":"
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C#NULL \u68c0\u67e5\u8fd0\u7b97\u7b26\uff08?.\uff09\u548c\u6cdb\u578b <\/h1>\n

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\u8cc7\u6df1\u5927\u4f6c : wuliiqq <\/span> <\/i> 11<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
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\u5982\u9898 \u521d\u5b66 c#\u8bed\u8a00\uff0c\u60f3\u7528 C#\u8bed\u8a00\u5b9e\u73b0\u4e00\u4e2a\u6cdb\u578b\u7c7b\u578b\u5355\u94fe\u8868 \u6709\u5982\u4e0b\u4ee3\u7801\uff1a<\/p>\n

class LinkedList<Anytype> {<\/p>\n

public Node<Anytype> Head;  public Anytype getFirst () {   return this.Head?.Data; } <\/code><\/pre>\n
}<\/p>\n
\u5728 getFirst \u65b9\u6cd5\u4e2d\uff0c\u6211\u4f7f\u7528\u4e86?.\u64cd\u4f5c\u7b26\uff0c\u51fa\u73b0\u4e86\u5982\u4e0b\u9519\u8bef: “\u8fd0\u7b97\u7b26\u201c?\u201d\u65e0\u6cd5\u5e94\u7528\u4e8e\u201cAnytype\u201d\u7c7b\u578b\u7684\u64cd\u4f5c\u6570”, \u6211\u627e\u4e0d\u5230\u4e3a\u4ec0\u4e48\u8fd9\u91cc\u4e0d\u80fd\u4f7f\u7528\u8fd9\u4e2a\u64cd\u4f5c\u7b26\u7684\u539f\u56e0\uff0c\u662f\u56e0\u4e3a Node \u662f\u6cdb\u578b\u7c7b\u578b\u7684\u539f\u56e0\u5417\uff1f \u70e6\u8bf7\u524d\u8f88\u89e3\u7b54\u3002<\/p>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (1<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
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  • \n
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     \u8cc7\u6df1\u5927\u4f6c : forgottencoast <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u8fd9\u53e5\u201creturn this.Head?.Data;\u201d
    \u7b49\u540c\u4e8e\u201creturn this.Head == null ? null : Head.Data;\u201d
    \u56e0\u4e3a Anytype \u6709\u53ef\u80fd\u662f struct\uff0c\u800c struct \u662f\u4e0d\u53ef\u4e3a null \u7684\uff0c\u6240\u4ee5\u4e0d\u80fd\u5728 this.Head == null \u6210\u7acb\u7684\u5206\u652f\u628a null \u4f5c\u4e3a\u8fd4\u56de\u503c\u3002
    \u56e0\u6b64\uff0c\u8fd9\u91cc\u4e0d\u80fd\u7528?.\u64cd\u4f5c\u7b26\u3002
    \u53d8\u901a\u7684\u6539\u6cd5\u662f return this.Head == null ? default(Anytype) : Head.Data;
    \u4f46\u662f\u6ca1\u6709\u8282\u70b9\u4ecd\u7136\u8fd4\u56de\u503c\u662f\u4e0d\u5bf9\u7684\uff0c\u8fd9\u6837\u65e0\u6cd5\u533a\u5206\u662f\u6ca1\u6709\u8282\u70b9\u8fd8\u662f\u8282\u70b9\u7684\u503c\u662f\u9ed8\u8ba4\u503c\u3002
    \u6240\u4ee5\uff0c.NetFramework \u8fd4\u56de\u7684\u662f LinkedListNode<T>\uff0c\u4e00\u4e2a class\uff0c\u53ef\u4e3a\u7a7a\u3002<\/p>\n
    \u53e6\u5916\uff1a\u6307\u5bfc\u624b\u518c\u5efa\u8bae\u4e0d\u7528 Anytype \u8fd9\u79cd\u5f88\u957f\u7684\u5199\u6cd5\uff0c\u5c31\u662f T \u3002
    \u4ee5\u53ca getFirst\uff0c\u4f1a\u5199\u51fa\uff1apublic LinkedListNode<T> First { get; }                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"
    C#NULL \u68c0\u67e5\u8fd0\u7b97\u7b26\uff08?.\uff09\u548c…<\/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\/127262"}],"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=127262"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/127262\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=127262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=127262"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=127262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}