可以使用String作为toString()更可靠的代替方法,因为它在用于null和undefined时仍然有效。例如: js constnullVar=null;nullVar.toString();// TypeError: nullVar is nullString(nullVar);// "null"constundefinedVar=undefined;undefinedVar.toString();// TypeError: undefinedVar is undefinedString(undefinedVar);/...
jsCopy to Clipboard function init() { var name = "Mozilla"; // name 是 init 创建的局部变量 function displayName() { // displayName() 是内部函数,它创建了一个闭包 console.log(name); // 使用在父函数中声明的变量 } displayName(); } init(); init() 创建了一个名为 name 的局部变量和...
When you create a string, your variable becomes a string object instance, and as a result has a large number ofproperties(即.XXX)andmethods(即.XXX())available to it. 您可以使用方括号符号返回字符串中的字符。 属性length:获取字符串或数组的长度。 注意:数组也有indexOf()和slice()方法。 方法ind...
String HTML wrapper methods like String.prototype.fontsize and String.prototype.big. String.prototype.substr probably won't be removed anytime soon, but it's defined in Annex B and hence normative optional. String.prototype.trimLeft and String.prototype.trimRight should be replaced with String....
Learn about the Window interface, including its properties and methods, specifications and browser compatibility.
Usingslice()to create a new string The following example usesslice()to create a new string. var str1 = 'The morning is upon us.'; var str2 = str1.slice(4, -2); console.log(str2); // OUTPUT: morning is upon u Usingslice()with negative indexes ...
Specification HTML #dom-settimeout-dev See also Polyfill ofsetTimeoutwhich allows passing arguments to the callback incore-js Window.clearTimeout() WorkerGlobalScope.setTimeout() Window.setInterval() Window.requestAnimationFrame() Window.queueMicrotask()...
There's also no option to pass a thisArg to setTimeout as there is in Array methods such as forEach() and reduce(). As shown below, using call to set this doesn't work either.jsCopy to Clipboard setTimeout.call(myArray, myArray.myMethod, 2.0 * 1000); // error setTimeout.call...
Element.insertAdjacentHTML() Element.outerHTML Parsing HTML or XML into a DOM tree:DOMParser Serializing a DOM tree into an XML string:XMLSerializer Element.getHTML() ShadowRoot.getHTML() Element.setHTMLUnsafe() ShadowRoot.setHTMLUnsafe()
Learn about the HTMLCollection interface, including its properties and methods, specifications and browser compatibility.