原文出处:https://blog.bitsrc.io/3-flavors-of-the-for-loop-in-javascript-and-when-to-use-them-f0fb5501bdf3 在学习任何开发语言时候,for循环是必不可少的一种语法,可能所有开发人员都会使用它。它非常经典,以至于每个开发语言都至少包括一种关于循环的语法版本。不过,在JavaScript种包含了三种不同的循环语法...
for( ; ; ) {// statements} JavaScriptfor循环示例 让我们举一些使用for循环的例子。 1) 、简单for循环示例 以下示例使用for循环语句,在控制台窗口中显示从 1 到 5 的数字。 for(varcounter =1; counter <5; counter++) {console....
This is not always the case, JavaScript doesn't care. Statement 2 is also optional.If statement 2 returns true, the loop will start over again, if it returns false, the loop will end.If you omit statement 2, you must provide a break inside the loop. Otherwise the loop will never end...
If expression 2 returns true, the loop will start over again. If it returns false, the loop will end. Note If you omit expression 2, you must provide abreakinside the loop. Otherwise the loop will never end. This will crash your browser. Read about breaks in a later chapter of this ...
JavaScript var i; for (i = 0; i <= 4; i++) { console.log(i); } Here, i is declared in line 1 separately. Inside the for loop's header in line 2, it's only assigned the value 0 to begin with. Now while this latter approach of setting up a loop is perfectly fine, it'...
Running the JavaScript code above will result in the following output. Output [ 0 ] [ 0, 1 ] [ 0, 1, 2 ] We set a loop that runs untili < 3is no longertrue, and we’re telling the console to print thearrayExamplearray to the console at the end of each iteration. With this ...
In JavaScript, the for loop is used for iterating over a block of code a certain number of times or over the elements of an array. In this tutorial, you will learn about the JavaScript for loop with the help of examples.
In this final chapter on flow control, we will look at another of the shell’s looping constructs.The for loop differs from the while and until loops in that it ...
具体可以参考:SyntaxError: continue must be inside loop - JavaScript | MDN 里面也提到了解决方法,使用return退出当前循环,以及使用for of代替forEach numbers.forEach(number=>{if(number ===2) {// 跳出当前循环return}console.log(number)// 1 3 4 5} ...
可以看到同样报错,continue不能在非循环语句中,原因是forEach的参数是一个回调函数,并不是循环语句,所以无法执行continue语句 具体可以参考:SyntaxError: continue must be inside loop - JavaScript | MDN 里面也提到了解决方法,使用 return 退出当前循环,以及使用 for of代替forEach js复制代码numbers.forEach(number...