The problem is that Array is actually under the umbrella ofObjectsdata type. Sotypeofis indeed returning truthfully. Unfortunately, that isn't really helpful for us who just want to check if the value is an array or not 🙊 #typeofTable ...
functionmyFunction(){varfruits=["Banana","Orange","Apple","Mango"];varx=document.getElementById("demo");x.innerHTML=Array.isArray(fruits);} 尝试一下 » 定义和用法 isArray() 方法用于判断一个对象是否为数组。 如果对象是数组返回 true,否则返回 false。
function func(){} 通过测试,使用如:str == String.constructor的形式,只能判断Object、Array、String、Boolean、Number,对于null、function、undefind这些会报异常。 参考: http://stackoverflow.com/questions/4775722/check-if-object-is-array http://www.jb51.net/article/21945.htm...
用我的理解来说,就是要判断一个Object是不是数组(这里不是口误,在JavaScript当中,数组实际上也是一种对象),如果这个Object的原型链上能够找到Array构造函数的话,那么这个Object应该及就是一个数组,如果这个Object的原型链上只能找到Object构造函数的话,那么它就不是一个数组。 const a = []; const b = {}; co...
Vue Js Check if a Variable is an Array: In Vue.js, you can use the Array.isArray() method to check if a variable is an array or not. This method takes one parameter, which is the variable you want to check, and returns a boolean value. If the variabl
p>数组nonExistantArray是否为空或存在:数组fineArray是否为空或存在:functioncheckArray() {letemptyArray = [];letnonExistantArray =undefined;letfineArray = [1,2,3,4,5];if(Array.isArray(emptyArray) && emptyArray.length) output =true;elseoutput =false;document.querySelector('.output-empty').te...
JavaScript语言中有可以是不是数组的方法，方法名是Array.isArray()，可以将字符串、数值、boolean值等判断数组。下面利用几个实例说明Array.isArray()方法的用法，操作如下：工具/原料 JavaScript eclipse Tomcat7.x JDK1.8 截图工具 浏览器 方法/步骤 1 第一步，打开eclipse开发软件，在web目录下新建静态页面，并...
Check if an object is an array: constfruits = ["Banana","Orange","Apple","Mango"]; letresult = Array.isArray(fruits); Try it Yourself » Check if another datatype is an array: lettext ="W3Schools"; letresult = Array.isArray(text); ...
//code to check if a value exists in an array using javascript for loop var fruits_arr = ['Apple', 'Mango', 'Grapes', 'Orange', 'Fig', 'Cherry']; function checkValue(value, arr) { var status = 'Not exist'; for (var i = 0; i < arr.length; i++) { var name = arr[...
This is the fastest method on Chrome, and most likely all other browsers. All arrays are objects, so checking the constructor property is a fast process for JavaScript engines. If you are having issues with finding out if an objects property is an array, you must first check if the propert...