JavaScript Instanceof运算符如何使用（代码示例）

下面是Instanceof运算符的示例。
例子：

< !DOCTYPE html> < html > < body > < center > < h1 style = "color:green" > lsbin< / h1 > < p id = "GFG" > < / p > < script > var a = ["Geeks", "for", "Geeks"]; document.getElementById("GFG").innerHTML = (a instanceof Array) + "< br > " + (a instanceof Number); < / script > < / center > < / body > < / html >

输出如下：

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运算符实例JavaScript中的ins用于在运行时检查对象的类型。它返回一个布尔值如果为true, 则表明该对象是特定类的实例；如果为false, 则它不是.
语法如下：

var gfg = objectName instanceof objectType

参数：
objectName：说明对象的名称。
示例1：objectTypes。

< !DOCTYPE html> < html > < body > < center > < h1 style = "color:green" > lsbin< / h1 > < p id = "GFG" > < / p > < script > var fruits = ["Apple", "Mango", "Banana"]; document.getElementById("GFG").innerHTML = (fruits instanceof Array) + "< br > " + (fruits instanceof Object) + "< br > " + (fruits instanceof String) + "< br > " + (fruits instanceof Number); < / script > < / center > < / body > < / html >

输出如下：

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示例2：证明String和Date对象也是Object的一种(从Object派生)。

< !DOCTYPE html> < html > < body > < h1 style = "color:green" > lsbin< / h1 > < p id = "GFG" > < / p > < script > var myString = new String(); var myDate = new Date(); console.log(myString instanceof Object); console.log(myString instanceof Date); console.log(myString instanceof String); console.log(myDate instanceof Date); console.log(myDate instanceof Object); console.log(myDate instanceof String); < / script > < / body > < / html >

输出如下