A symbol is a unique and immutable data type. It may be used as an identifier for object properties. The Symbol object is an implicit object wrapper for the symbol primitive data type. Syntax Symbol([description]) Parameters description Optional Optional, string. A description of the symbol whi...
InJavaScript, Symbol is aprimitive value. A value having the data typeSymbolcan be referred to as a "Symbol value". In a JavaScript runtime environment, a symbol value is created by invoking the functionSymbol, which dynamically produces an anonymous, unique value. A symbol may be used as ...
Symbol是ES6引入的新类型,所以在ES5的基础上,JS就有了字符串(string)、数字型(number)、布尔(bool)、null、undefined和Symbol共六种基本类型(bigint ES2016 添加)。 In JavaScript, Symbol is a primitive value. Symbol是一种原始数据类型 什么是原始数据类型 A value having the data type "symbol" can be r...
在SVG中,就有专门的<symbol>标签,用来指代SVG小图标。 在这里,Symbol又有了另外的角色,作为一个JavaScript的原生数据类型(primitive data type)存在。 说到JavaScript原生数据类型,我们通常想到的有这6种:undefined、null、boolean、string、number、object。而symbol是ES6新增的一个原生数据类型。 而Symbol本身又是一个...
functionisSymbol(value){if(!value)returnfalseif(typeofvalue!=='object')returnfalseif(!value.constructor)returnfalseif(value.constructor.name!=='Symbol')returnfalseif(!value.__SymbolData__||value.__SymbolData__!==value)returnfalseif(value[value.constructor.toStringTag]!=='Symbol')returnfalseretu...
Confusingly, the symbol's description contains the substringLegacy. This wasa later addition to the specthat doesn't have much of a paper trail (and is older than the contemporary specification's "legacy" terminology—that is, it didn't have a defined meaning at the time). I think we sh...
Value of All the symbol properties can be set to be a data type of function. Function is a data type derived frommapbox-gl-style(version 0.18.0 with additional support of "identity"), as it defines: A function allow you to make the appearance of a map feature change with the current...
Symbol 是一种特殊的、不可变的数据类型,可以作为对象属性的标识符使用,表示独一无二的值。Symbol 对象是一个 symbol primitive data type 的隐式对象包装器。它是JavaScript语言的第七种数据类型,前6种分别是:Undefined、Null、Boolean、String、Number、Object。