When working with arrays in JavaScript, one common task is calculating the sum of all the numbers contained within that array. Whether you’re developing a web application, analyzing data, or just experimenting with code, knowing how to efficiently sum an array can save you time and effort. ...
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 ...
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 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", "...
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'...
const castArray = (value) => (Array.isArray(value) ? value : [value]); 案例 castArray(1); // [1] castArray([1, 2, 3]); // [1, 2, 3] 1. 2. 3. 4. 5. 6. 7. 8. 9. 检查数组是否为空 js // `arr` is an array ...
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:', ...
Sum : 21 Product : 720 Flowchart:ES6 Version:// Declare and initialize an array of numbers const array = [1, 2, 3, 4, 5, 6]; // Initialize variables for sum (s) and product (p) let s = 0; let p = 1; // Iterate through the array using a for...of loop for (const ...
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) ...