FOR…OF循环 for…of _loop_是一个相对较新的迭代语法,用于遍历可迭代对象(如数组、字符串等)的值。例如: let array = [1, 2, 3, 4, 5]; for (let value of array) { console.log(value); } 这段代码会打印数组中的每个元素值。 for循环是一种强大的工具,在JavaScript开发中无处不在。掌握它的...
In JavaScript, the for loop is used for iterating over a block of code a certain number of times, or to iterate over the elements of an array. Here's a quick example of the for loop. You can read the rest of the tutorial for more details. Example for (let i = 0; i < 3; i...
但是ES6中有新的entries方法可以让for...in...也可以获取索引。 for (let [index, val] of arr.entries()) { console.log(index); } 总结 当遍历Array时候,在需要索引时候推荐用forEach,不需要索引时候用for...of...。 当迭代Object时候,虽然只能用for...in...配合hasOwnproperty过滤不需要的,但我还是...
functiondoObjForLoop3(obj){ letstartTime = performance.now(); for(let[key, value]ofObject.entries(obj)){ // console.log(key, value); } letendTime = performance.now(); console.log((endTime - startTime) +"ms"); } functiondoObjForLoop4(obj){ letstartTime = performance.now(); Obj...
for(leti =0; i <5; i++) { text +="The number is "+ i +""; } Try it Yourself » From the example above, you can read: Expression 1 sets a variable before the loop starts (let i = 0). Expression 2 defines the condition for the loop to run (i must be less than 5). ...
2.1、 使用 for-in 通常,我们可以使用for-in来遍历数组的内容,代码如下: constarr = [1,2,3];letindex;for(indexinarr) {console.log(“arr[“ + index + “] = “ + arr[index]);} 一般来说,操作的结果如下: arr[0]=1arr[1]=2arr[2]=3 ...
Let's look at an example: for (var counter = 5; counter > 0; counter--) { console.log(counter + ' - Inside for loop on TechOnTheNet.com'); } console.log(counter + ' - Done for loop on TechOnTheNet.com'); In this for loop example, the counter variable is decremented as ...
You’ll see in the examples how each of these clauses is translated into code. So let’s start right away. Using simpleforloops The most typical way to useforloops is counting. You just need to tell the loop where to start, where to finish, and with what pace to count. This is ho...
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...
In the above example, we initialized theforloop withlet i = 0, which begins the loop at0. We set the condition to bei < 4, meaning that as long asievaluates as less than4, the loop will continue to run. Our final expression ofi++increments the count for each iteration through the ...