The questions below were asked in a preliminary check before the actual interview. The role itself was for a “JavaScript Engineer”. This particular set of questions is from a job I applied to over a year ago. I’ve chosen to share them here because I think readers of this blog would ...
functionduplicate(array){varinitialLength =array.length;// Store the initial lengthfor(vari =0; i < initialLength; i++) {array.push(array[i]);// Push a duplicate of each element}returnarray;} constarr = [1,2,3];constnewArr = dupl...
map(el => el()); console.log(newArray); // [0, 1, 2] 问题4 : 不会溢出JavaScript并发模型基于“事件循环”。 当我们说“浏览器是 JS 的家”时我真正的意思是浏览器提供运行时环境来执行我们的JS代码。浏览器的主要组件包括调用堆栈,事件循环,任务队列和Web API。像setTimeout,setInterval和Promise...
Now our array scripts have 4 elements inside it and we can print or access them by using their index number. Note that index number starts from 0. To get the third element of the array we have to use the index number 2. Here is the way to get the third element of an array. ...
Q23: 如何为Array对象添加你自定义的函数,使得如下代码可以正常工作。 话题: JavaScript难度: ⭐⭐⭐⭐ var arr = [1, 2, 3, 4, 5]; var avg = arr.average(); console.log(avg); JavaScript是一个基于原型的语言。也就是说对象之间通过原型链接,并继承其函数。为了给Array对象添加函数,我们可以...
You use the push method of the array object: var a = [1,2]; a.push(3); // a now is [1,2,3]; 32) How do you remove an element from a JavaScript Array? There are two ways to do this, depending on whether you want to remove an element from the beginning or the end of ...
Object.keys(counterArray).length // Output 3 本文给出的面试题答案只是很多合理答案中的几个,可能会不全面,欢迎大家补充。 由于个人疏忽等原因,本文中难免会存在少量错误,欢迎大家批评指正。面试题参考自: 21 Essential JavaScript Interview Questions | Codementor ...
counterArray["C"] = 1; 其实答案很简单,直接计算key的数量就可以了。 Object.keys(counterArray).length // Output 3 面试题参考自:21 Essential JavaScript Interview Questions | Codementor 本文给出的面试题答案只是很多合理答案中的几个,可能会不全面,欢迎大家补充。
How can you create an Array in JavaScript? 您可以使用数组文字来定义数组,如下所示: var x=[]; var y=[1, 2, 3, 4, 5]; 1. 2. How to read elements of an array in JavaScript? 数组的长度属性对于迭代很有用。我们可以如下读取数组的元素- ...
isNaN("");// false - hmm...isNaN("45");// false - this is a string, I thoughtisNaN([]);// false - wait so an empty array is a number?isNaN([1,2]);// trueisNaN({});// trueisNaN(()=>{});// true Copy You may already be familiar with the differences between==...