如果找到一个 item,则返回 item 从尾向前检索第一个次出现在数组的位置。数组的索引开始位置是从 0 开始的。如果在数组中没找到指定元素则返回 -1。提示: 如果你想查找数组首次出现的位置,请使用 indexOf() 方法。浏览器支持所有主要浏览器都支持lastIndexOf()属性,但是在Internet Explorer 8 及更早IE版本不...
例如:arr.lastIndexOf(7) --- 从后往前找第一个7,索引值为6,所以结果就是6。 2.两个参数时,arr.lastIndexOf(4,6) --- 在索引0---6之间找4,其索引值为4,所以结果就是4。 arr.lastIndexOf(4,3) --- 在索引0---3之间找4,其中没有4,所以返回-1 语法:array.IndexOf(item,start) 参数: 返...
get last item in an arraylist get last item in an list in vb.net Get latest added id using Dapper - Insert query Get List by IDs Get method name that generated the exception? Get MimeType of Bitmap object Get Multiple item counts from a single LINQ Query Get next index value in list...
❮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
Default is the last element (array.length-1). Negative start values counts from the last element (but still searches from right to left). Return Value TypeDescription A numberThe position of the specified item. -1 if the item is not found. ...
JavaScript // Create an array. var ar = ["ab", "cd", "ef", "ab", "cd"]; // Determine the first location, in descending order, of "cd". document.write(ar.lastIndexOf("cd") + ""); // Output: 4 // Find "cd" in descending order, starting at index 2. document...
Check if 1 is First/Last Element in Array Write a JavaScript program to check whether 1 appears in the first or last position of a given array of integers. The array length must be larger than or equal to 1. The program verifies if the number 1 is present at either the first or last...
JavaScript built-in: Array: findLastIndex Global usage 94.53% + 0% = 94.53% IE ❌ 6 - 10: Not supported ❌ 11: Not supported Edge ❌ 12 - 96: Not supported ✅ 97 - 134: Supported ✅ 135: Supported Firefox ❌ 2 - 103: Not supported ✅ 104 - 136: Supported ✅ 137...
Name Array.lastIndexOf() — search backward through an array Availability ECMAScript 5 Synopsis array.lastIndexOf(value) array.lastIndexOf(value, start) Arguments value The value … - Selection from JavaScript: The Definitive Guide, 6th Edition [Book]
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]) ...