执行L15 for 循环走了足够多次后,V8 收集到足够的feedback后会重新建立假设来做优化,不过这次的假设是「入参可能是 number 也可能是 string」—— 这意味着调用的时候要多判断入参类型是 string 还是 number 从而导致了最终的性能劣化 (一模一样的代码要 243 ...
AI代码解释 asyncfunctionopen(path,flags,mode){mode=modeNum(mode,0o666);path=getPathFromURL(path);validatePath(path);validateUint32(mode,'mode');returnnewFileHandle(awaitbinding.openFileHandle(pathModule.toNamespacedPath(path),stringToFlags(flags),mode,kUsePromises));} src/node_file.cc 代码语...
AI代码解释 exports.unserialize=function(obj,originObj){varisIndex;if(typeofobj==='string'){obj=JSON.parse(obj);isIndex=true;}originObj=originObj||obj;varcircularTasks=[];varkey;for(keyinobj){if(obj.hasOwnProperty(key)){if(typeofobj[key]==='object'){obj[key]=exports.unserialize(obj[key...
类型: string | null CLI: --jsx.fragment <fragment> 默认: "React.Fragment" or nullRollup 用来创建 JSX 片段的元素函数。对于 React,这通常是 React.Fragment,对于其他框架,则是 Fragment。在 "preserve" 模式下,如果指定了 jsx.importSource,则将确保片段在作用域中,否则同名的全局变量不会被局部变量覆盖...
First, we need to create the Mongoose schema in/users/models/users.model.js: constuserSchema =newSchema({firstName:String,lastName:String,email:String,password:String,permissionLevel:Number}); Once we define the schema, we can easily attach the schema to the user model. ...
log(1 instanceof Number) //false a = new String('a') console.log(a instanceof String) // true b = new Number(1) console.log(b instanceof Number) // true typeof: 返回类型字符串 delete: 删除对象或者对象的属性 in: 指定的属性是否在对象内,返回bool值 let s = new Array('a',...
URI uri=builder.build();//创建http GET请求HttpGet httpGet =newHttpGet(uri);//执行请求response =httpclient.execute(httpGet);//判断返回状态是否为200if(response.getStatusLine().getStatusCode() == 200) { resultString= EntityUtils.toString(response.getEntity(), "UTF-8"); ...
map.addSource('LineString',{ 'type':'geojson', 'data':geojson }); map.addLayer({ 'id':'LineString', 'type':'line', 'source':'LineString', 'layout':{ 'line-join':'round', 'line-cap':'round' }, 'paint':{ 'line-color':'#BF93E4', ...
Pass the constructor a string. You will get back a JSDOM object, which has a number of useful properties, notably window: const dom = new JSDOM(`<!DOCTYPE html>Hello world`); console.log(dom.window.document.querySelector("p").textContent); // "Hello world" (Note that jsdom will pa...
执行L15 for 循环走了足够多次后,V8 收集到足够的feedback后会重新建立假设来做优化,不过这次的假设是「入参可能是 number 也可能是 string」—— 这意味着调用的时候要多判断入参类型是 string 还是 number 从而导致了最终的性能劣化 (一模一样的代码要 243 毫秒才跑完,慢了有三倍吧)。 1. assumption 被打...