/* Will display:01234foo*/ 因此,为了使你的代码没有错误,永远不要将“for...in...”应用于数组。 3、 数组上的“forEach”方法 由于“for...in...”不适用于数组。 应该有更好的迭代 JavaScript 数组的方法。 所以 ES5 引入了数组的迭代方法。 在我...
for-in循环应该用在非数组对象的遍历上,使用for-in进行循环也被称为“枚举”。 从技术上将,你可以使用for-in循环数组(因为JavaScript中数组也是对象),但这是不推荐的。因为如果数组对象已被自定义的功能增强,就可能发生逻辑错误。另外,在for-in中,属性列表的顺序(序列)是不能保证的。所以最好数组使用正常的for循...
Why Use For Loops in JavaScript Code In JavaScript, just as in other programming languages, we use loops to read or access the items of a collection. The collection can be an array or an object. Every time the loop statement cycles through the items in a collection, we call it an itera...
因此,为了使你的代码没有错误,永远不要将“for...in...”应用于数组。 3、 数组上的“forEach”方法 由于“for...in...”不适用于数组。 应该有更好的迭代 JavaScript 数组的方法。 所以 ES5 引入了数组的迭代方法。 在我看来,这种改进使 JavaScript 变得优雅。 迭代方法很多,适用于不同的使用场景: Array...
JS Loops/Conditionals break continue do-while loop for loop for-in loop if-else switch while loop JS String Methods JS Number Methods JS Math Functions JS Array Methods This JavaScript tutorial explains how to use the for loop with syntax and examples. ...
In the following sections, we will discuss each of these loop statements in detail.The while LoopThis is the simplest looping statement provided by JavaScript.The while loop loops through a block of code as long as the specified condition evaluates to true. As soon as the condition fails, ...
We hear a lot about loops, especiallyforloops. So what, in fact, are they? They’re just pieces of code that repeat the same commands several times, until you reach a desired conclusion, without getting you bored out of your mind, repeating your code. This is how we JavaScript guys do...
JavaScript - For...in Loop - The for...in loop in JavaScript is used to loop through an object's properties. The JavaScript for...in loop is a variant of the for loop. The for loop can't be used to traverse through the object properties. So, the for...in
The result is it loops only twice, one for element one and two, and one for element three. At the end, you got index2, but the length of the array is1. letarr = ['x','y','z'];for(leti =0; i <= arr.length; i++) {letprop = arr.shift();console.log(prop);console.log...
For loops are the most used loops in any language. But there is more than one way to iterate using a for loop. These are the ways you can use the for loop in JavaScript. The advantages and disadvantages are given too. The Old fashion way. ...