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);/...
函数是 JavaScript 中的基本组件之一。JavaScript 中的函数类似于过程——一组执行任务或计算值的语句。但要成为函数,这个过程应该接受输入并返回与输入存在某些明显关系的输出。要使用一个函数,你必须将其定义在你希望调用它的作用域内。
JSON exists as a string — useful when you want to transmit data across a network. It needs to be converted to a native JavaScript object when you want to access the data. This is not a big issue — JavaScript provides a global JSON object that has methods available for converting between...
Date Date.prototype.toLocaleFormat(), which used a format string in the same format expected by the strftime() function in C, is obsolete. Use toLocaleString() or Intl.DateTimeFormat instead.Array Non-standard Array generic methods like Array.slice(myArr, 0, 12), Array.forEach(myArr, my...
Eventschangeandinput Supported Common Attributesautocomplete,inputmode,maxlength,minlength,pattern,placeholder,readonly,required, andsize IDL attributesselectionStart,selectionEnd,selectionDirection, andvalue DOM interfaceHTMLInputElement Methodsselect(),setRangeText(), andsetSelectionRange() ...
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()
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()...
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 ...
The serialization of the DOM tree read from the property does not include shadow roots— if you want to get a HTML string that includes shadow roots, you must instead use the Element.getHTML() or ShadowRoot.getHTML() methods. Similarly, when setting element content using innerHTML, the HTM...
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...