--checkJS 选项下 .js 文件中的错误 在TypeScript 2.2 之前,类型检查和错误报告只能在.ts文件中使用。从 TypeScript 2.3 开始,编译器现在可以对普通的.js文件进行类型检查并报告错误。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 let foo = 42; // [js] Property 'toUpperCase' does not exist on...
或者一个定义了却未赋初值的变量// Objectstypeof{a:1} ==='object';typeof[1,2,4] ==='object';// 使用Array.isArray或者Object.prototype.toString.call方法//可以分辨出一个数组和真实的对象typeofnewDate() ==='object';typeofnewBoolean(true) ==='object'// 令人困惑.不要这样使用type...
console.log(typeofstr);//stringconsole.log(typeofarr);//objectconsole.log(typeofobj);//objectconsole.log(typeofnum);//numberconsole.log(typeofb);//booleanconsole.log(typeofn);//null是一个空的对象console.log(typeofu);//undefinedconsole.log(typeoffn);//function 通过上面的检测我们发现type...
varexp=null;if(typeofexp=="null"){alert("is null");} 为了向下兼容,exp 为 null 时,typeof null 总返回 object,所以不能这样判断 代码语言:javascript 代码运行次数:0 运行 AI代码解释 <script type="text/javascript">functiontestuser(){vari=document.getElementByIdx_x("aa");if(i.value=="null...
Type: object cwd Type: string Default: process.cwd() Current working directory of the project to retrieve the diagnostics for. typingsFile Type: string Default: The types property in package.json. Path to the type definition file you want to test. This can be useful when using a test runne...
vara=null;(!a&&typeofa==="object");// true nullis the only primitive value that is “falsy” (aka false-like; seeChapter 4) but which also returns"object"from thetypeofcheck. So what’s the seventh string value thattypeofcan return?
var checker = apiCheck.func.withProperties({ type: apiCheck.oneOfType([apiCheck.object, apiCheck.string]), help: apiCheck.string.optional }); function winning(){} winning.type = 'awesomeness'; checker(winning); // <--pass function losing(){} checker(losing); // <-- fail...
--strict:在类型检查(例如使用了--checkJs)时使用严格模式 --noEmit:不生成任何文件,只查错。 这样就可以简单地检查.js源代码中可能隐含的类型错误。其中的一部分是通过JSDoc引入类型信息时的错误(例如找不到某个类型);另一部分则是静态检查.js源代码的错误,例如试图访问某个不存在的属性。这些检查与在TypeScrip...
WebTorrent is also available as a standalone script (webtorrent.min.js) which exposesWebTorrenton thewindowobject, so it can be used with just a script tag: <scripttype='module'>importWebTorrentfrom'webtorrent.min.js'</script> The WebTorrent script is also hosted on fast, reliable CDN infrastr...
the map's style. The only required parameter foraddLayeris a Mapbox style layer object. It also accepts an optionalbeforeparameter, which is the ID of an existing layer to insert the new layer before. If you omit this argument, then the renderer will draw the layer on top of the map....