, checkTokenAndGetIndex = function (classList, token) { if (token === "") { throw new DOMEx( "SYNTAX_ERR" , "An invalid or illegal string was specified" ); } if (/\s/.test(token)) { throw new DOMEx( "INVALID_CHARACTER_ERR" , "String contains an invalid character" ); } r...
JS中数据类型分为原始数据类型(5种)和引用数据类型(Object类型)。 1)5种原始数据类型:Undefined、Null、Boolean、Number和String。需要注意的是JS中字符串属于原始数据类型。 2)typeof运算符:查看变量类型,对变量或值调用typeof运算符将返回下列值之一: undefined – 如果变量是 Undefined 类型的 boolean – 如果变量...
number – 如果变量是 Number 类型的 string – 如果变量是 String 类型的 object – 如果变量是一种引用类型或 Null 类型的 代码语言:javascript 复制 functionfoo(){}console.log(typeof8);// numberconsole.log(typeoffoo);// functionconsole.log(typeof("nfit"));// stringconsole.log(typeofjQuery);/...
Check if a string includes "world": lettext ="Hello world, welcome to the universe."; letresult = text.includes("world"); Try it Yourself » More examples below. Description Theincludes()method returnstrueif a string contains a specified string. ...
const hasClass = (el, className) => el.classList.contains(className); hasClass(document.querySelector('p.special'), 'special'); // true 9.hide:隐藏所有的指定标签 const hide = (...el) => [...el].forEach(e => (e.style.display = 'none')); ...
A return in an else if block following an if block that contains a return can be separated into multiple if blocks. eslint: no-else-return // bad function foo() { if (x) { return x; } else { return y; } } // bad function cats() { if (x) { return x; } else if (y) ...
objRef; private ElementReference elementRef; private string display = "inline-block"; private string message = "Select one of these list items."; private string color = "initial"; protected override async Task OnAfterRenderAsync(bool firstRender) { if (firstRender) { module = await JS....
static get(key: string): string 读取指定键的值。如果密钥不存在,该方法将引发错误。使用该contains方法检查钥匙串中是否存在钥匙。 Alert 显示模态弹窗。类似web ui中的Modal组件 使用它来配置以模态或表单形式呈现的弹窗。配置弹窗后,调用 presentAlert() 或 presentSheet() 以呈现弹窗。这两种表示方法将返回一个...
overloading in JavaScript. To understand this, let's say we have a method calledgreetwhich can take a single string and also a list of strings. To make ourgreetmethod workable in both situation we need to know what kind of parameter is being passed: is it single value or list of ...