while loop in JavaScript

while loop: As long as the condition is true, the loop body code will be executed repeatedly

while (conditional judgment)

{

If the condition is true, the loop body code will be executed

}

While loop structure description:

Before the loop starts, it must Initialize the variable (declare the variable and give the variable an initial value).
If the condition of while is true, the code ({ }) in the loop body will be executed repeatedly. If the condition is false, exit the loop.
In the loop body, there must be a "variable update" statement. In other words: the values of the variables in the two loops cannot be the same. If they are the same, it will cause an "infinite loop".

Let’s learn through examples:

Output all numbers between 1-10

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>php.cn</title>
        <script> 
        var i = 1;
        while(i<=10){
            document.write(i);
            i++ //变量更新，是为了避免出现“死循环”
        }
        </script>
    </head>
    <body>
    </body>
</html>

Loop statement There must be three elements, one of which is indispensable:

Variable initialization
Conditional judgment
Variable update

Output all odd numbers between 1-100

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>php.cn</title>
        <script> 
        //变量初始化
        var i = 1;
        //条件判断
        while(i<=100){
            //如果是奇数，则输出
            if(!(i%2==0)){
                document.write(i+"  ");
            }
            //变量更新
            i++;
        }
        </script>
    </head>
    <body>
    </body>
</html>

Continuing Learning

new file

<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>php.cn</title> <script> var i = 1; while(i<=10){ document.write(i); i++ //变量更新，是为了避免出现“死循环” } </script> </head> <body> </body> </html>

submit Reset Code

Automatic operation

while loop in JavaScript

ElementaryImperial CMS enterprise imitation website tutorial

ElementaryNewbies with zero foundation in WordPress build personal blogs and corporate websites

ElementaryUltimate CMS zero-based website building instruction video

ElementaryFront-end project-Shangyou [HTML/CSS/JS technology comprehensive practice]

IntermediateVue3.0 from 0 to build a universal backend management system project practice

ElementaryZero-based front-end course [Vue advanced learning and practical application]

ElementaryWEB front-end tutorial [HTML5+CSS3+JS]

ElementaryQuick introduction to apipost

IntermediateVue3+TypeScript practical tutorial-enterprise-level project practice

ElementaryLet's briefly talk about starting a business in PHP

IntermediateVUE e-commerce project (front-end & back-end dual project actual combat)

ElementaryApipost practical application [api, interface, automated testing, mock]