JavaScript Code: // Define a function named first_last_1 with a parameter numsfunctionfirst_last_1(nums){// Calculate the index of the last element in the arrayvarend_pos=nums.length-1;// Check if the first or last element in the array is equal to 1, and return the resultreturnnums[...
#JavaScript This article discusses the preferred way to retrieve the last element of an Array in JavaScript. Tip 7 in this Useful JavaScript Hacks Article proposes the following method to get the last item in an array. syntax1.js var array = [1,2,3,4,5,6];console.log(array.slice(-...
❮PreviousJavaScript ArrayReferenceNext❯ Example 1 Find the last element with a value over 18: constages = [3,10,18,20]; ages.findLastIndex(checkAge); functioncheckAge(age) { returnage >18; } Try it Yourself » Description
❮PreviousJavaScript ArrayReferenceNext❯ Example 1 Find the value of the last element with a value over 18: constages = [3,10,18,20]; functioncheckAge(age) { returnage >18; } functionmyFunction() { document.getElementById("demo").innerHTML= ages.findLast(checkAge); ...
无涯教程-Javascript - lastIndexOf()函数 JavaScript array.lastIndexOf()方法返回可以在数组中找到给定元素的最后一个索引,如果不存在,则返回-1。从fromIndex开始向后搜索数组。 lastIndexOf() - 语法 array.lastIndexOf(searchElement[, fromIndex]);
数组中的searchElement的最后一个匹配项的索引;如果未找到searchElement,则为 -1。 备注 lastIndexOf方法在数组中搜索指定的值。该方法返回第一个匹配项的索引;如果找不到指定的值,则为 -1。 搜索按降序索引顺序进行(首先搜索最后一个成员)。若要按升序顺序搜索,请使用indexOf 方法 (Array) (JavaScript)。
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]) ...
Vue Js lastindexOf Method : The last index (position) of a given value is returned by the lastIndexOf() method. The search defaults to beginning at the last element and ending at the first. Negative start values begin counting with the previous
if (k in t && t[k] === searchElement) { return k; } } return -1; }; } 可以使用 ES5-Slim 使旧版浏览器完全兼容ES5语法。 为什么要避免使用for in 不过要注意的是,在Array.prototype上面附加方法后,for in语法也会把lastIndexOf方法也枚举出来: ...
In this tutorial, you will learn about the JavaScript Array lastIndexOf() method with the help of examples. The lastIndexOf() method returns the index of the last occurrence of a specified element in the array.