function getLastElementChild(obj){ if(obj.lastElementChild != undefined){ return obj.lastElementChild; }else{ var nodeLast = obj.lastChild; while(nodeLast && nodeLast.nodeType != 1){ nodeLast = nodeLast.previousSibling; } return nodeLast; } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10...
const array = [5, 12, 8, 130, 44] const found = array.find(element => element > 10) const foundIndex = array.findIndex(element => element > 10) console.log(found) // 12 console.log(foundIndex) // 1 reduce() && reduceRight() reduce() 方法对数组中的每个元素执行一个由你提供的...
创建一个新的数组,其中每一个元素由调用数组中的每一个元素执行提供的函数得来(creates a new array with the results of calling a provided function on every element in the calling array)。map 方法会给原数组中的每个元素都按顺序调用一次 callback 函数。callback 每次执行后的返回值(包括 undefined)组合...
「语法」 arr.find((element,index,array), thisArg) element: 当前元素 index: 当前元素索引可选 array: 数组本身可选 thisArg: 执行回调时用作this的对象。可选 // 从数据中找出第一个满足特定条件的对象constdata = [ {name:'张三',article:3}, {name:'老王',article:9}, {name:'老李',article:10}...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 /* * @Description: * @Author: 微信公众号: 前端自学社区 * @Date: 2021-08-07 00:53:51 * @LastEditTime: 2021-08-07 00:53:51 * @LastEditors: Do not edit */constdata=[{date:'2021-8-1',income:200},{date:'2021-8-2',income:400...
const newArray = array.filter(callback(element[, index[, array]])[, thisArg]) callback:用来测试数组的每个元素的回调函数,返回true表示该元素通过测试,保留该元素,false则不保留。它接受以下三个参数: element:数组中当前正在处理的元素。 index:可选,正在处理的元素在数组中的索引。
4. Last Elements of Array Write a JavaScript function to get the last element of an array. Passing the parameter 'n' will return the last 'n' elements of the array. Test Data: console.log(last([7, 9, 0, -2])); console.log(last([7, 9, 0, -2],3)); ...
std::cout << "First element: " << arr.front() << std::endl; std::cout << "Last element: " << arr.back() << std::endl; return 0; }使用at 和边界检查实例 #include <iostream> #include <array> int main() { std::array<int, 3> arr = {1, 2, 3}; try { std::cout <...
ThelastIndexOf()method returns -1 if the value is not found. ThelastIndexOf()starts at a specified index and searches from right to left (from the given postion to the beginning of the array). By defalt the search starts at the last element and ends at the first. ...
If you want to remove the last element from a multidimensional array, you can use thepop()method. Remove Element From Outer Array letstudentsData = [["Jack",24], ["Sara",23]];// remove the array element from outer arraystudentsData.pop();console.log(studentsData);// Output: [ [ '...