不同类型的循环 JavaScript 支持不同类型的循环: for- 循环代码块一定的次数 for/in- 循环遍历对象的属性 while- 当指定的条件为 true 时循环指定的代码块 do/while- 同样当指定的条件为 true 时循环指定的代码块 For 循环 for 循环是您在希望创建循环时常会用到的工具。 下面是 for 循环的语法: for (语句...
So, here’s what our while loop looks like after getting it tofollow good programming conventions (‘best practices’): vari=0;while(i<5){alert('Hi!');i++;} Believe it or not, there is a much faster, better and easier way to do this using JavaScript! It’s by using afor loop:...
Later on in this page, once we discover the while loop, we'll extend this code to keep repeating the input prompt as long as the entered value is not valid. As we shall see later on in the JavaScript Conditionals chapter, and even in general throughout this course, tons and tons of ...
在前端开发过程中,我们经常使用到JavaScript 提供了很多种循环和迭代的方法,常见for, for…of, for…in, while, Array.forEach, 以及 Array.* (还有一些 Arra...
The JavaScript for/in statement loops through the properties of an object:Example var person = {fname:"John", lname:"Doe", age:25}; var text = "";var x;for (x in person) { text += person[x]; } Try it yourself » The While Loop...
JavaScript Tutorials JavaScript while and do...while Loop JavaScript for... of Loop JavaScript for...in loop JavaScript continue Statement JavaScript break Statement JavaScript Iterators and Iterables JavaScript for loopIn JavaScript, the for loop is used for iterating over a block of code...
whileanddo...whilestatements areconditionally based, they execute when a given statement returns as evaluating totrue. Similar in that they are also conditionally based,forstatements also include extra features such as aloop counter, allowing you to set the number of iterations of the loop ...
javascript中forin循环 js for in循环用法 分类 普通for循环 自行指定循环次数。 for (i = 0; i < loopTimes; i++) { console.log(i); } 1. 2. 3. 1 for..in循环 属历史遗留,用于遍历对象的属性(数组的索引值也算属性)。 但有一个缺点:如果手动向数组添加成员属性,则:...
There are several ways to iterate over things in JavaScript. Most notable way is to use loops. Loop constructs includes for, forEach, do...while, while, for...in and for...of. All these constructs loops over synchronous iterables such as arrays, objects,
JavaScript的重复机制为循环(loop) for:适合重复动作已知次数的循环。...1.初始化(initialization):初始化只在循环开始时发生 2.测试条件(test condition):测试条件检查循环是否要再继续 3.动作(action):循环里的动作就是每一轮循环实际重复执行的代码...4.更新(update):循环里的负责更新每一轮循环的循环变量。....