Getting the last element of an array is a frequently encountered scenario, and you must have your own commonly used methods. Maybe there's a moment when you're thinking as much as I am: "How does it count to be elegant?". Suppose we have the following array: let arr = ['cat','do...
Are you wondering how to get the last element of an array in JavaScript? JavaScript has a lot of built-in methods that can be used to manipulate arrays. Let’s find out what we can implement to access the last element of the array. Using length property Suppose, you have an array an...
varmyArray=[1,2,,,6];// Fastest method, requires the array is in a variablemyArray[myArray.length-1];// Also very fast but it will remove the element from the array also, this may or may not matter in your case.myArray.pop();// Slowest but very readable and doesn't require a...
if(value instanceof Array) { //对数组执行某些操作 } 2)获取对象的类型,比较是否为object类型(此方法只能检测是否为Object,不推荐) if(typeof(value)=="Object") { //对数组执行某些操作 } 3)检测对象是否为数组,使用Array.isArray()方法(只支持ie9+,firefox 4+,safari 5+,opera 10.5+和chrome) if(...
当我们需要查找某个值位于数组中的那个项的时候我们就可以使用indexOf、lastIndexOf方法。 indexOf 方法 返回某个值在数组中的第一个匹配项的索引。 语法 array1.indexOf(searchElement[,fromIndex]) 参数 array1,必须、且为一个数组对象。 searchElement,必须,为array1中定位的值。
{varfruits = ["Banana", "Orange", "Apple", "Mango"];varx=document.getElementById("demo"); x.innerHTML=fruits.constructor; } length 定义和用法 length 属性可设置或返回数组中元素的数目。 语法 //设置数组的数目array.length=number//Return the length of an array 返回一个数组的长度array.length...
您可以使用已移至Stage 4 in Aug, 2021的Array.at()方法
Array对象允许在一个变量中存储多个值。它存储相同类型元素的固定大小的顺序集合。数组用于存储数据集合,但将数组看作同一类型变量的集合通常更有用。本文主要介绍JavaScript(JS) array.lastIndexOf(searchElement[, fromIndex]) 方法。 原文地址:JavaScript(JS) array.lastIndexOf(searchElement[, fromIndex])...
JavaScript 数组的 lastIndexOf() 方法 Array.lastIndexOf()方法与Array.indexOf()方法功能相似,但它返回的是指定元素在数组中最后一次出现的位置。 例如,在一个包含多个相同元素的数组中搜索特定元素“Banana”的最后位置: constfruits=["Apple","Banana","Orange","Banana","Mango"];letposition=fruits.lastInde...
for (var element of arr) //遍历数组 { if (newArr.indexOf(element) === -1) //如果这个元素,不在新数组中 { newArr.push(element) //则添加 } } return newArr //返回新数组 } console.log(unique(arr)) 1. 2. 3. 4. 5. 6. ...