Using the Array.prototype.forEach() Method If you prefer a more explicit approach without usingreduce, theforEachmethod can also be used to sum an array. While it may not be as concise, it offers clarity in terms of what each part of the code is doing. ...
In javascript, we can calculate the sum of the elements of the array by using the Array.prototype.reduce() method. The reduced method for arrays in javascript helps us specify a function called reducer function that gets called for each of the elements of an array for which we are calling ...
（一）array()函数：传统与现代的交融 PHP的array()函数是创建数组的瑞士军刀，既能构造索引数组，也能打造关联数组：php // 索引数组 $fruits = array('Apple', 'Banana', 'Orange');// 关联数组 $person = array('name' => 'John', 'age' => 30, 'city' => 'New York');（二）方括号语法：...
console.log(aN2.indexOf(2,3));//5 从第4项开始算起,所以取的是第二个2,位置为5 console.log(aN2.lastIndexOf(2,5));//5 从第6项即第二个2开始从尾往前找,所以找到是第6项那个2,它的位置是5 console.log(aN2.lastIndexOf(2,4));//1 从第5项即6这个数字从尾往前找,所以找到是第2项那...
function getSum(array){ for (var i = 0; i < array.length; i++){ sum += parseInt(array[i]); } return sum; } console.time("getSum"); for (var i = 0; i < 1000000; i++){ sum = 0; getSum(arr); } console.timeEnd("getSum"); // 7877.155ms ...
constfruits=newArray('Apple','Banana');console.log(fruits.length); 数组文字表示法 使用数组文本声明,我们指定数组将具有的值。如果我们不声明任何值,数组将为空。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 // 'fruits' array created using array literal notation.constfruits=['Apple','Banana'...
function arraySum(arr) { var sum = 0; if (Object.prototype.toString.call(arr) === '[object Array]') { for (var i = 0; i < arr.length; i++) { if (typeof arr[i] === "number" && !isNaN(arr[i])) { sum += arr[i]; } else { va...
alert(sum);//15 4、数组concat()方法 //concat() 方法用于连接两个或多个数组。//该方法不会改变现有的数组,而仅仅会返回被连接数组的一个副本。//语法//arrayObject.concat(arrayX,arrayX,...,arrayX)varcolors = ["red", "green", "blue"];varcolors2 = colors.concat("yellow", ["black", "...
initialValue);console.log(sumWithInitial) 15. reverse reverse()方法将反转数组并返回对相同数组的引用,第一个数组元素成为最后一个,最后一个数组元素成为第一个。换句话说,数组中的元素顺序将转向与之前相反的方向。 array.reverse(); const array1 = ['one', 'two', 'three'];console.log('array1:', ...
1、Array.unshift(newEle , newEle2 , newEle3 , ...)(改变原数组) 向数组的开头添加一个或更多元素,并返回新的长度 队列方法 栈数据结构的访问规则是LIFO(Last-In-First-Out,后进先出),而队列数据结构的访问规则是FIFO(First-In-First-Out,先进先出) ...