{"id":93829,"date":"2020-04-17T04:52:59","date_gmt":"2020-04-16T20:52:59","guid":{"rendered":"http:\/\/4563.org\/?p=93829"},"modified":"2020-04-17T04:52:59","modified_gmt":"2020-04-16T20:52:59","slug":"%e8%af%b7%e6%95%99%e4%b8%80%e4%b8%8b%e4%b8%80%e4%b8%aa%e4%bd%bf%e6%88%91%e9%9c%87%e6%83%8a%e7%9a%84-js-%e8%af%ad%e6%b3%95-%e6%b2%a1%e9%94%99%ef%bc%8c%e7%9c%8b%e8%b5%b7%e6%9d%a5%e5%be%88%e5%83%8f","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=93829","title":{"rendered":"\u8bf7\u6559\u4e00\u4e0b\u4e00\u4e2a\u4f7f\u6211\u9707\u60ca\u7684 js \u8bed\u6cd5 ?.(\u6ca1\u9519\uff0c\u770b\u8d77\u6765\u5f88\u50cf\u4e09\u76ee\u4f46\u5374\u4e0d\u662f:\u800c\u662f.)"},"content":{"rendered":"
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\u8bf7\u6559\u4e00\u4e0b\u4e00\u4e2a\u4f7f\u6211\u9707\u60ca\u7684 js \u8bed\u6cd5 ?.(\u6ca1\u9519\uff0c\u770b\u8d77\u6765\u5f88\u50cf\u4e09\u76ee\u4f46\u5374\u4e0d\u662f:\u800c\u662f.) <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : devwolf <\/span> <\/i> 20<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
\u4e3e\u4f8b
let a = {a:”1″,b:”2″}
console.log(a?.a)<\/p>\n

\u5951\u673a\uff1a\u53e6\u4e00\u4e2a\u7ec4\u7684\u540c\u4e8b\u5728\u4e00\u4e2a angular \u9879\u76ee\u91cc\u53d1\u73b0\u4e86\u8fd9\u4e2a\u8bed\u6cd5\u7684\u4f7f\u7528\uff0c
\u901a\u8fc7\u5173\u952e\u5b57\u67e5\u4e86\u4e00\u4e0b\u4e5f\u5c31\u8fd9\u4e48\u4e2a csdn \u7684\u7ed3\u679c
\u300a angular \u4e2d\u7684 ? \u548c !\u300b https:\/\/blog.csdn.net\/weixin_30908941\/article\/details\/95594290<\/p>\n

\u91cc\u9762\u9664\u4e86\u4ea4\u4ee3?\u53ef\u4ee5\u5224\u65ad\u524d\u9762\u7684\u53d8\u91cf\u662f\u5426\u4e3a null \u6216 undefined \u518d\u6267\u884c\u540e\u9762,\u8fd8\u6709\u4e2a!\u5224\u65ad\u540e\u9762\u952e\u6240\u5bf9\u5e94\u7684\u503c\u662f\u5426\u4e3a null \u6216 undefined\uff0c\u4e0d\u8fc7\u6ca1\u6709\u6210\u529f\u5728 js \u91cc\u518d\u73b0\u8fd9\u4e2a!\u3002<\/p>\n

\u5c31\u6211\u4e2a\u4eba\u5728\u7f51\u4e0a\u7684\u641c\u7d22\u7ed3\u679c\u6765\u770b\uff0c\u611f\u89c9\u8fd9\u4e2a?.\u7684\u5199\u6cd5\u6bd4!!\u8fd8\u8981\u51b7\u95e8\uff0c\u7528\u9014\u7684\u6548\u679c\u4e0a\u4e2a\u4eba\u611f\u89c9\u7c7b\u4f3c react \u5199 jsx \u8fdb\u884c\u9875\u9762\u6e32\u67d3\u65f6\u7684&&\u6216\u8005?:<\/p>\n

\u5f53\u7136,\u6211\u81ea\u5df1\u7684\u8fd9\u4e9b\u80a4\u6d45\u731c\u6d4b\u603b\u7ed3\u4e5f\u6ca1\u4ec0\u4e48\u8425\u517b\uff0c\u8fd8\u8bf7\u5404\u4f4d\u6709\u4e86\u89e3\u6216\u8005\u611f\u5174\u8da3\u7684\u5206\u6790\u4e00\u6ce2\u8fd9\u4e2a?.\u5417 <\/p><\/div>\n

\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (100<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Flourite <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8fd9\u8bed\u6cd5\u5728\u5176\u4ed6\u8bed\u8a00\u4e5f\u4e0d\u662f\u5f88\u7f55\u89c1\u7684\uff0c\u6bd4\u5982 swift <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : asAnotherJack <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    kotlin \u4e5f\u6709\u8fd9\u79cd\u8bed\u6cd5 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : mercury233 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u53ef\u7a7a\u7c7b\u578b\uff0c\u4e0d\u7b97\u51b7\u95e8 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : murmur <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \uff1f\u3002\u8fd9\u8bed\u6cd5\u592a\u8d85\u524d\u4e86\uff0c\u867d\u7136\u5404\u79cd objectPath \u7c7b\u7ec4\u4ef6\u65e9\u5c31\u5728\u7528\uff0c\u53ef\u4ee5\u4e00\u6b21\u8bbf\u95ee\u5f88\u6df1\u5c42\u7684\u8282\u70b9\uff0c\u4e0d\u7528\u4e00\u5c42\u5c42\u5224\u7a7a <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : cmdOptionKana <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u73b0\u5728\u4e3b\u6d41\u8bed\u8a00\u662f\u5929\u4e0b\u8bed\u6cd5\u4e00\u5927\u6284\uff0c\u8d8a\u6765\u8d8a\u8d8b\u540c\u4e86\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : skies457 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Optional Chaining, https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Operators\/Optional_chaining <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : devwolf <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u611f\u8c22\u4e0a\u7684\u5404\u4f4d\u89e3\u7591\uff0c\u539f\u6765\u662f\u5176\u4ed6\u8bed\u8a00\u5df2\u7ecf\u5b58\u5728\u7684\u8bed\u6cd5\uff0cget \u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Lin0936 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6700\u8fd1\u5728 kotlin \u91cc\u5199\u8fd9\u4e2a\u90fd\u5199\u5410\u4e86. \u4e4b\u524d swift \u7684\u9879\u76ee\u91cc\u4e5f\u7528\u5230\u5f88\u591a. <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : yaphets666 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u5199\u4e86\u4e00\u5e74\u591a js \u4e5f \u4e0d\u77e5\u9053\u8fd9\u4e2a…\u6211\u662f\u4e0d\u662f\u592a\u83dc\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : crs0910 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4f60\u8fd8\u53ef\u4ee5\u4f7f\u7528 ?? \u6765\u4ee3\u66ff ||\uff0c\u907f\u514d\u9700\u8981\u5224\u65ad\u503c\u662f\u4e0d\u662f 0 \u8fd9\u79cd\u60c5\u51b5
    \u5173\u952e\u8bcd\uff1aNullish Coalescing <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : vivipure <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    dart \u4e5f\u6709\u3002\u8fd9\u662f ES2020 \u7684\u65b0\u8bed\u6cd5\uff0c\u633a\u597d\u7528\u7684\uff0c\u4e0d\u7528\u5728\u5199\u4ec0\u4e48 a && a.b \u4e4b\u7c7b\u7684\u4e86\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : aaronlam <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u521a\u5f00\u59cb\u770b\u5230\u65f6\uff0c\u6211\u4e5f\u662f\u5f88\u9707\u60ca\u7684\u3002
    \u4f46\u662f\u5b9e\u8bdd\u5b9e\u8bf4\uff0c\u8fd9\u4e2a\u8bed\u6cd5\u7684\u786e\u5f88\u5b9e\u7528\uff0c\u4e0d\u5bf9\u5417\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : littleylv <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5199 swift \u7684\u65f6\u5019\u7ecf\u5e38\u8fd9\u4e48\u5199\u3002\u73b0\u5728\u7684\u8bed\u8a00\u5f88\u591a\u90fd\u5f00\u59cb\u4e92\u901a\u6709\u65e0\u4e86\uff0c\u90fd\u4f1a\u76f8\u4e92\u501f\u9274\u5bf9\u65b9\u7684\u4e00\u4e9b\u4e1c\u897f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : oneisall8955 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    kotlin \u91cc\u9762\u6709\uff0cthymeleaf \u6a21\u677f\u5199\u5bf9\u8c61\u5224\u65ad\u975e\u7a7a\u4e5f\u662f\u7528\u8fd9\u91cc\u7684\u8bed\u6cd5 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : islxyqwe <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u65b0\u7248\u672c ts \u63d0\u524d\u652f\u6301\u7684 Optional Chaining \u7b49 ES2020 \u7684\u65b0\u8bed\u6cd5\u62c9 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : liuy1994g <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    es \u91cc\u8fd8\u5728\u63d0\u6848\u5427 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : noobma <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5173\u6ce8 ts \u7684\u8bdd\u5e94\u8be5\u4e0d\u4f1a\u89c9\u5f97\u8fd9\u4e2a\u5199\u6cd5\u51b7\u95e8 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Justin13 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5efa\u8bae\u5173\u6ce8 ECMA262 repo <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : luob <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5199 js \u7684\u4e0d\u90fd\u662f\u5929\u5929\u8ddf\u7740\u6700\u65b0\u8bed\u6cd5\u6807\u51c6\u8d70\u5417\uff0c\u8fd9\u79cd\u6700\u8fd1\u5927\u534a\u5e74\u90fd\u5728\u8c08\u7684\u8bed\u6cd5\u5c31\u7b97\u6ca1\u7528\u8fc7\uff0c\u603b\u4e0d\u81f3\u4e8e\u6ca1\u542c\u8fc7\u5427\u2026\u2026<\/p>\n

    \u8fd8\u662f\u8bf4\u73b0\u5728\u524d\u7aef\u5df2\u7ecf\u8db3\u591f\u6210\u719f\uff0c\u5927\u5bb6\u90fd\u4e0d\u5b66\u65b0\u5185\u5bb9\u4e86\uff1f <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : crz <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e3b\u8981\u662f\u65b0\uff0c\u51b7\u95e8\u5e94\u8be5\u4e0d\u81f3\u4e8e\uff0c\u6bd5\u7adf\u5f88\u5b9e\u7528 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : g00001 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u89c9\u5f97\u8fd8\u662f aardio \u4e2d\u7684\u76f4\u63a5\u4e0b\u6807\u66f4\u7b80\u6d01\u597d\u7528\uff0c
    if( a[[b]] ){ } \u4e0d\u7ba1 a \u662f\u4ec0\u4e48\u90fd\u4e0d\u4f1a\u629b\u5f02\u5e38\uff0c\u4e0d\u662f\u5bf9\u8c61\u8fd4\u56de null\uff0c\u53ef\u4ee5\u8282\u7701\u597d\u591a\u4ee3\u7801\u3002<\/p>\n

    \u6bd4 swift,kotlin,js \u4ec0\u4e48\u7684\u51fa\u73b0\u65e9\u591a\u4e86\uff0c\u56fd\u4ea7\u5c0f\u8bed\u8a00\u4e5f\u662f\u6709\u4eae\u70b9\u7684\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : baozijun <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Safe calls are useful in chains. For example, if Bob, an Employee, may be assigned to a Department (or not), that in turn may have another Employee as a department head, then to obtain the name of Bob’s department head (if any), we write the following:<\/p>\n

    bob?.department?.head?.name
    Such a chain returns null if any of the properties in it is null. <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : sarlanori <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C#\u4e5f\u6709\u8fd9\u4e2a\u8bed\u6cd5\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : murmur <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @luob \u6d4f\u89c8\u5668\u7aef\u4e0d\u6562\u778e babel\uff0c\u6bd4\u4e0d\u4e86\u540e\u7aef\u53ef\u4ee5\u81ea\u5df1\u51b3\u5b9a\u7248\u672c <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xianxiaobo <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6709\u610f\u601d\uff0c\u5b66\u5230\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : yhxx <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @liuy1994g \u5df2\u7ecf\u8fdb stage4 \u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : jadehare <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ts \u6709\u63d2\u4ef6\u4f1a\u81ea\u52a8\u4e0d\u4e0a\u3002\u3002\u867d\u7136\u6211\u81ea\u5df1\u5199\u8fd8\u662f if \u5224\u65ad\u4e00\u4e0b <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : zmqking <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    c# \u91cc\u9762\u4e5f\u6709\uff01 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : 9ki <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8981\u591a\u60f3 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Lax <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e3a\u4e86\u51cf\u5c11\u5bf9\u7236\u5143\u7d20\u7684\u7a7a\u7f6e\u5224\u5b9a\uff0c\u5c24\u5176\u662f\u5f88\u591a\u4e2a\u7ea7\u522b\u3002
    a.b.c.d \u8fd9\u79cd\uff0cif(a) { if(a.b) { if(a.b.c) { a.b.c.d }}}}\uff0c\u4e0d\u60f3\u4e00\u7ea7\u4e00\u7ea7\u5224\u65ad\u7684\u65f6\u5019\u5c31\u5f88\u65b9\u4fbf\u4e86\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : goodboy95 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u63e1\u8349\uff0c\u521a\u521a\u8bd5\u4e86\u4e00\u4e0b\uff0c\u9664\u4e86?.\u8fd0\u7b97\u7b26\u4e4b\u5916\uff0c??\u8fd0\u7b97\u7b26\u4e5f\u88ab\u652f\u6301\u4e86\uff01
    var a = {sa: 3, sb: 4};
    var b = null;
    console.log(a?.sa ?? 5); \/\/ 3
    console.log(b?.sa ?? 5); \/\/ 5 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : yolee <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    c# \u4e5f\u662f\u7528\u8fd9\u4e2a\u5224\u65ad\u662f\u5426\u4e3a\u7a7a\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : lower <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8bed\u6cd5\u7cd6 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Veneris <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    dart \u4e5f\u6709 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    https:\/\/caniuse.com\/#feat=mdn-javascript_operators_optional_chaining
    \u592a\u8d85\u524d\u4e86\uff0cFF \u548c CR \u5404\u53ea\u8fc7\u4e86\u4e24\u4e2a\u7248\u672c\uff0c\u8fc7 babel \u53ef\u884c\uff08 angular \u53ef\u4ee5\u7528\u5927\u6982\u5c31\u662f babel \u7684\u539f\u56e0\uff1f\uff09
    \u65e9\u524d coffee \u5c31\u770b\u5230\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : lithbitren <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ?? \u548c || \u6709\u5565\u533a\u522b\u554a <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : liukangxu <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u770b\u6765 C#\u8fd8\u662f\u6709\u4eba\u7528\u7684\u3002\u3002\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : apeople <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    angular \u4e5f\u53ea\u662f\u80fd\u5728\u6a21\u677f\u4e2d\u4f7f\u7528\u5427\uff0c\u8981\u60f3\u5728 ts \u4e2d\u4f7f\u7528\u8fd8\u662f\u5f97\u914d\u7f6e babel \u63d2\u4ef6\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : DivineRapierH <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @Lax #30 \u8fd9\u79cd\u6211\u4e00\u76f4\u662f\u7528 lodash \u7684 get \u4e00\u628a\u68ad <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Removable <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C#\u91cc\u6211\u7ecf\u5e38\u8fd9\u4e48\u7528\uff0c\u6bd4\u5224\u65ad==null \u65b9\u4fbf\u591a\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : redam <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @luob \u554a\uff0c\u8001\u54e5\u4e00\u822c\u662f\u5728\u54ea\u91cc\u4e86\u89e3\u8fd9\u4e9b\u65b0\u5185\u5bb9\u7684\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : devwolf <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @lithbitren
    https:\/\/developer.mozilla.org\/zh-CN\/docs\/Web\/JavaScript\/Reference\/Operators\/Nullish_coalescing_operator
    \u6458\u5f55:
    \u7531\u4e8e || \u662f\u4e00\u4e2a\u5e03\u5c14\u903b\u8f91\u8fd0\u7b97\u7b26\uff0c\u5de6\u4fa7\u7684\u64cd\u4f5c\u6570\u4f1a\u88ab\u5f3a\u5236\u8f6c\u6362\u6210\u5e03\u5c14\u503c\u7528\u4e8e\u6c42\u503c\u3002\u4efb\u4f55\u5047\u503c\uff08 0\uff0c ”\uff0cNaN\uff0cnull\uff0cundefined \uff09\u90fd\u4e0d\u4f1a\u88ab\u8fd4\u56de\u3002\u8fd9\u5bfc\u81f4\u5982\u679c\u4f60\u4f7f\u7528 0\uff0c”\u6216 NaN \u4f5c\u4e3a\u6709\u6548\u503c\uff0c\u5c31\u4f1a\u51fa\u73b0\u4e0d\u53ef\u9884\u6599\u7684\u540e\u679c.
    \u7a7a\u503c\u5408\u5e76\u64cd\u4f5c\u7b26??\u53ef\u4ee5\u907f\u514d\u8fd9\u79cd\u9677\u9631\uff0c\u5176\u53ea\u5728\u7b2c\u4e00\u4e2a\u64cd\u4f5c\u6570\u4e3a null \u6216 undefined \u65f6\uff08\u800c\u4e0d\u662f\u5176\u5b83\u5047\u503c\uff09\u8fd4\u56de\u7b2c\u4e8c\u4e2a\u64cd\u4f5c\u6570\u3002<\/p>\n

    \u611f\u8c22#10 \u63d0\u4f9b\u4e86\u62d3\u5c55\u548c\u7ebf\u7d22 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : lithbitren <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @devwolf \u87f9\u87f9\uff0cMDN \u5e38\u770b\u5e38\u65b0\u554a <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Ritter <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    666 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : gromit1337 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @vivipure #11 \u5bf9\u5bf9 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : iugo <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    VS Code + TypeScript \u4f1a\u7ed9\u6211\u5f3a\u63a8\u8fd9\u79cd\u5199\u6cd5. <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : iugo <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    tc39 \u8fd8\u662f\u8981\u8ba2\u9605\u4e00\u4e0b\u7684: https:\/\/github.com\/tc39\/proposal-optional-chaining https:\/\/github.com\/tc39\/proposals\/blob\/master\/finished-proposals.md <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : iugo <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u63a8\u4e00\u4e0b\u524d\u4e24\u5929\u6211\u4eec\u5173\u4e8e nullish coalescing operator post: https:\/\/zsqk.github.io\/news\/2020-04-08-nullish-coalescing-operator.html <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : klgd <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e0a\u6b21\u9047\u89c1\u4e86\u4e00\u6b21\uff0c\u641c\u4e86\u534a\u5929\u624d\u77e5\u9053\u662f\u5e72\u4ec0\u4e48\u7684
    \u8fd8\u6709`!!` <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ZZITE <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Optional Chaining
    \u53bb\u5e74\u5199\u7684 ts \u9879\u76ee\u5c31\u5728\u7528\u4e86\uff0c\u5728 react \u9879\u76ee\u4e2d\u5f88\u8212\u670d\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : lneoi <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8fd9\u662f\u65b0\u8bed\u6cd5\u5566\uff0c\u5f88\u5b9e\u7528\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : AlynxZhou <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u770b\u8d77\u6765\u4e3b\u6ca1\u5199\u8fc7 coffeescript \u554a\uff0ccoffeescript \u91cc\u9762\u6709\u8fd9\u4e2a\u95ee\u53f7\u8fd0\u7b97\u7b26 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : jtwor <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    c# \u7a7a\u8fd0\u7b97 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Rwing <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5f88\u68d2\u7684\u8bed\u6cd5\u554a\uff0cc#\u9996\u521b\u7684\u5427\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : luzemin <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C#\u7684\u8bed\u6cd5\u7cd6 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : est <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ruby \u91cc\u53ef\u4ee5\u76f4\u63a5 inline \u5916\u6302\u4e00\u4e2a exception \u66f4\u65b9\u4fbf\u3002\u4e0d\u7ba1\u662f . \u6302\u4e86\u8fd8\u662f\u522b\u7684\u4ec0\u4e48\u6302\u4e86\u90fd\u80fd\u6b63\u5e38\u6267\u884c\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xuchdeid <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    TypeScript \u554a \u3002\u3002\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : IllBeBack <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u76f8\u5f53\u4e8e Ruby \u7684\u5355\u8eab\u72d7\u8fd0\u7b97\u7b26 a&.a<\/p>\n

    ruby-china.org\/topics\/30415 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ershierdu <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5b66 swift \u7684\u65f6\u5019\u611f\u89c9\u8fd9\u4e2a\u6709\u70b9\u7ed5\uff0c\u9879\u76ee\u505a\u5b8c\u540e\u4e0d\u518d\u5199 swift \u5c31\u5fd8\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : wszgrcy <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ts 3.7 \u7684\u8bed\u6cd5\u5427 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : mrleft <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u7ed9\u4f60\u770b\u4e2a\u80fd\u98de\u5347\u7684
    https:\/\/react-course.magicfun.ai\/css\/styled-components-how.html <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : g00001 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    c# 6.0 \uff08 2015 \u5e74\uff09 \u624d\u6709 Null \u6761\u4ef6\u8fd0\u7b97\u7b26\uff0c\u5e94\u5f53\u662f\u6bd4\u8f83\u665a\u4e86\u3002<\/p>\n

    \u56fd\u4ea7\u5c0f\u8bed\u8a00 aardio \u5728\u5341\u591a\u5e74\u524d\u5c31\u6709\u4e86\u7c7b\u4f3c\u7684\u8bed\u6cd5\uff0c\u4e0d\u4ec5\u4ec5\u662f\u5bf9\u8c61\uff0c\u4efb\u4f55\u5bf9\u8c61\u90fd\u53ef\u4ee5 if( a[[b]] ){ } \uff0c\u771f\u6b63\u7684\u6709\u9e2d\u5b50\u7684\u58f0\u97f3\u5c31\u53ef\u4ee5\u5f53\u9e2d\u5b50\u7528\uff0c\u8bf4\u5230\u5077\u61d2\u8fd9\u4e2a\u4e8b\uff0c\u6211\u4eec\u8fd8\u662f\u884c\u7684\u3002<\/p>\n

    \u53ea\u80fd null \u5bf9\u8c61\uff0c\u8fd8\u662f\u4f1a\u6709\u9ebb\u70e6\uff0c\u5982\u679c\u662f\u5176\u4ed6\u7c7b\u578b\u5462\uff0c\u8fd8\u662f\u8981\u5199\u5224\u65ad\uff0c\u5077\u61d2\u8fd8\u662f\u4e0d\u591f\u5f7b\u5e95\u8fd9\u4e0d\u884c\u7684\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : jin7 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    php \u65e9\u5c31\u6709\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ansenJ <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ES7+\u540e\u7684\u65b0\u8bed\u6cd5 \u6211\u77e5\u9053\u6709 \u4f46\u662f\u4e0d\u77e5\u9053\u5728\u54ea\u4e2a\u7248\u672c\u91cc <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : optional <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    js \u751f\u6001\u5c31\u8981\u7ecf\u5e38\u4e0a\u6765\u770b\u770b tc39\uff0cts \u53ef\u4ee5\u7ecf\u5e38\u770b\u770b roadmap <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ccyu220 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u9664\u4e86 ts , \u6682\u65f6\u8fd8\u4e0d\u6562\u7528\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : g00001 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    PHP \u5c31\u66f4\u665a\u4e86\uff0cPHP 7 \u624d\u6709 $d = $a->$b->$c ?? ‘DEFAULT’ \u7684\u5199\u6cd5\uff0c\u4e0d\u662f\u5f88\u7b80\u6d01\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : chouchoui <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C#\u57fa\u672c\u64cd\u4f5c\uff0cts \u4e5f\u6709 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xrr2016 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Dart \u91cc\u9762\u7ecf\u5e38\u7528…\u8fd8\u6709 ?? \u8bed\u6cd5 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Chingim <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u591a\u5173\u6ce8 tc39 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : en20 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6700\u8fd1\u5199 flutter\uff0c\u770b\u522b\u4eba\u7684\u5e93\u7ecf\u5e38\u8fd9\u79cd\u8bed\u6cd5 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : overflow99 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5f88\u6709\u7528 \u5b66\u4e60\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : mingtianjiayou <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u65b0\u8bed\u6cd5\u54c8\u54c8 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : nekochyan <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6ca1\u8bb0\u9519\u7684\u8bdd\u662f es7 \u65b0\u8bed\u6cd5\u5427\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u4e0d\u6562\u7528\uff0c\u6015\u4e0d\u652f\u6301 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : shenyu1996 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6700\u8fd1\u65b0\u5f00\u9879\u76ee \u4e0b\u610f\u8bc6\u5728\u4f7f\u7528 ?. … \u8fd9\u4e9b\u8bed\u6cd5
    \u8bf4\u771f\u7684 \u80fd\u5c11\u6389\u597d\u591a\u5934\u53d1 \u5c11\u4e9b\u597d\u591a\u4ee3\u7801 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xg4 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @nekochyan \u5df2\u7ecf\u7eb3\u5165\u6807\u51c6\uff0c\u53ef\u4ee5\u7528 babel \u8fdb\u884c\u517c\u5bb9\u5904\u7406 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : shenyu1996 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    “`
    {
    name: ‘aaa’,
    …(true && {age: 10})
    }
    “`<\/p>\n

    \u6bd4\u5982\u50cf\u8fd9\u79cd\u795e\u5947\u7684\u5199\u6cd5 \u771f\u7684\u80fd\u8ba9\u81ea\u5df1\u5c11\u6389\u597d\u51e0\u6839\u5934\u53d1 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Felldeadbird <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u5370\u8c61\u4e2d PHP7 \u4e5f\u6709\u8fd9\u79cd\u8bed\u6cd5\u3002\u4f46\u662f\u6211\u8fd8\u662f\u559c\u6b22\u7528\u4f20\u7edf\u7684:?\u5224\u65ad\u4e3a\u4e3b\u3002 \u592a\u65b0\u7684\u8bed\u6cd5\u6211\u6015\u5176\u4ed6\u4eba\u8c03\u5f0f\u51fa\u9519\u3002\u5c31\u8499\u853d\u4e86\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : cnit <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    thymeleaf \u91cc\u9762\u7ecf\u5e38\u4f1a\u7528\u5230 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : cbais7890 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u53ef\u9009\u94fe\u554a, \u5982\u679c\u7528\u8fc7 Swift \u80af\u5b9a\u4f1a\u89c9\u5f97\u5f88\u719f\u6089
    \u5b9e\u9645\u4e0a a?.b \u5c31\u7b49\u4e8e a && a.b \u7684\u610f\u601d, \u9632\u6b62\u5bf9\u4e0d\u5b58\u5728\u7684\u53d8\u91cf\u8bfb\u53d6\u5c5e\u6027\u800c\u4ea7\u751f\u5f02\u5e38
    \u5728\u5904\u7406\u67d0\u4e9b\u524d\u540e\u7aef\u4ea4\u4e92\u7684\u4e0d\u7a33\u5b9a\u6570\u636e\u65f6\u76f8\u5f53\u8212\u670d <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : LukeChien <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u73b0\u5728\u5f88\u5e38\u89c1\u4e86\uff0c\u4ee5\u524d\u5728\u6a21\u677f\u5f15\u64ce\u8bed\u6cd5\u91cc\u5f88\u5e38\u89c1 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : yxcoder <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u56e0\u4e3a js \u91cc\u9762\u8bbf\u95ee undefined \u6216\u8005 null \u7684\u6210\u5458\u4f1a\u62a5\u9519\uff0c\u6240\u4ee5\u5982\u679c\u8c03\u7528\u5f88\u6df1\uff0c\u8b6c\u5982\u8fd9\u79cd\uff0ca.b.c.d.e.f\uff0c\u4e3a\u4e86\u9632\u6b62\u62a5\u9519\uff0c\u8981\u8fd9\u4e48\u5199<\/p>\n

    a?a.b?a.b.c?a.b.c.d?a.b.c.d.e?a.b.c.d.e.f:null:null:null:null:null<\/p>\n

    \u5de8\u96be\u770b
    \u6240\u4ee5\u51fa\u4e86\u4e2a\u8bed\u6cd5\u7cd6<\/p>\n

    a?.b?.c?.d?.e?.f <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Pursue9 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C# \u8fd8\u6709 ?? ??=<\/p>\n

    a?.b \u7b49\u540c\u4e8e if(a == null) return null
    \u8fd8\u6709 a??0 \u7b49\u540c\u4e8e if(a == null) return 0
    a??=0 \u7b49\u540c\u4e8e if(a == null){ a = 0; return a;} <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : SilentDepth <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @Pursue9 #83 Logical Assignment Operators\uff0cES \u8fd9\u8fb9\u5df2\u7ecf Stage 3\uff0c\u5982\u65e0\u610f\u5916\u660e\u5e74\u5c31\u7eb3\u5165\u89c4\u8303\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : IGJacklove <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8fd8\u597d\u5427\uff0cflutter \u65e9\u5c31\u6709\u8fd9\u4e2a\u8bed\u6cd5\u4e86\uff0ckotlin \u4e5f\u6709\u7c7b\u4f3c\u7684\u8bed\u6cd5\uff0c\u7b80\u5355\u6765\u8bf4\u5c31\u662f\u7b80\u5316\u5224\u7a7a\u64cd\u4f5c\u7684\uff0cjs \u542c\u8bf4\u8981\u65b0\u52a0\u8fd9\u4e2a\u8bed\u6cd5\uff0c\u5f53\u65f6\u8dd1\u4e86\u662f\u8fd8\u4e0d\u80fd\u7528\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : SilentDepth <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Optional Chaining \u4e0d\u4ec5\u6709 foo.bar?.qux \uff0c\u8fd8\u6709 foo.bar?.( ) \u5462
    \ud83d\ude42 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : LeiNaD <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u53ef\u9009\u94fe <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : bilberry <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    ES2020 \u91cc\u9762\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : bilberry <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @bilberry https:\/\/www.freecodecamp.org\/news\/javascript-new-features-es2020\/ <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : weyou <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Python PEP505\uff0c\u4e0d\u8fc7\u8fd9\u8bed\u6cd5\u786e\u5b9e\u6709\u70b9 magic\uff0c\u4e0d\u7b26\u5408 Python \u7684\u4e00\u8d2f\u98ce\u683c\uff0c\u96be\u602a\u8fd8\u6ca1\u88ab\u91c7\u7eb3 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : somebody <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5f88\u591a\u8bed\u8a00\u90fd\u6709\uff0c\u8fd9\u4e2a\u53eb Safe navigation operator, Wikipedia \u6709 18 \u79cd\u8bed\u8a00\u7684\u4f8b\u5b50
    https:\/\/en.wikipedia.org\/wiki\/Safe_navigation_operator <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : jinliming2 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @yxcoder \u60a8\u8fd9\u4e2a\u5c31\u7b97\u6ca1\u6709 ?. \u8bed\u6cd5\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u7528 ?: \u554a\u2026\u2026
    \u7528 ?: \u662f\u4e11\uff0c\u4f46\u662f\u76f4\u63a5
    a && a.b && a.b.c && a.b.c.d && a.b.c.d.e && a.b.c.d.e.f || null
    \u4e5f\u7a0d\u5fae\u597d\u770b\u4e00\u4e9b\u554a\u2026\u2026
    \uff08\u867d\u7136\u8fd8\u662f ?. \u66f4\u9999 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : HytonightYX <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u8fd8\u5199\u8fc7 webpack \u7684\u5b9e\u73b0\uff0c\u4e0d\u8fc7\u53ea\u662f\u7528\u4e86\u6b63\u5219\u66ff\u6362\u6765\u5224\u65ad\uff0c\u4e0d\u662f\u5f88\u5b8c\u7f8e\u3002
    TC39 \u6709\u5173\u4e8e\u53ef\u9009\u94fe\u7684\u89e3\u91ca\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : hst001 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5f88\u597d\u7528\u7684\u8bed\u6cd5\u7cd6\uff0c\u5404\u5927\u8bed\u8a00\u5e94\u8be5\u5f15\u5165 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : errolli <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    C#\u91cc\u9762\u5c31\u6709\u3002\u3002\u3002 \u540e\u6765\u6362\u5230\u7528 Java \u7684\u516c\u53f8\u5c31\u6ca1\u8fd9\u4e2a\u5f85\u9047\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : FutherAll <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    optional \u66f4\u9002\u5408\u7528\u6765\u89e3\u5305\u5224\u7a7a\u4e4b\u7c7b\u7684\u3002
    \u5982\u679c\u7528\u6765\u5224\u65ad\u5e03\u5c14\u7684\u8bdd\u662f\u6709\u6b67\u4e49\u7684\uff0c\u6bd4\u5982\uff1aif (a?.b == 0)\u6216\u8005 if(a?.b == false)\uff0c\u5230\u5e95\u662f a \u4e3a\u7a7a\u8fd8\u662f a \u4e0d\u4e3a\u7a7a b \u4e3a false \u6216\u8005 b \u4e3a\u7a7a <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : param <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u539f\u6765 JS \u4e5f\u6709\u4e86 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Yumwey <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u53ef\u9009\u94fe\uff0c\u9999\u7684\u5f88\u3002\u9707\u60ca\u5565 TS \u5f3a\u63a8 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : guolaopi <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u5199 C#\uff0c\u8fd9\u73a9\u610f\u513f\u90fd\u5199\u4e86\u597d\u51e0\u5e74\u4e86\uff0c\u57fa\u672c\u5c31\u662f\u65e5\u5e38\u3002\u3002\u3002\u3002\u3002
    \u5b66\u65b0\u8bed\u8a00\u7684\u65f6\u5019\u89c9\u5f97\u6ca1\u6709 x?.x \u8fd8\u6709 x??y \u8fd9\u79cd\u5199\u6cd5\u5f88\u522b\u626d\u3002\u3002\u3002\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ugu <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    angular \u91cc\u9762\u7ecf\u5e38\u5199 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"

    \u8bf7\u6559\u4e00\u4e0b\u4e00\u4e2a\u4f7f\u6211\u9707\u60ca\u7684 js \u8bed\u6cd5…<\/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\/93829"}],"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=93829"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/93829\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=93829"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=93829"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=93829"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}