console 命令行工具 X clear

console

//利用3种循环来计算1+2+3+…+100的值。
//1、for循环
    function sum1() {
        var result1 = 0;
        for (var i=1; i <= 100; i++) {
            result1 += i;
        }
        return result1
    }
    document.write(sum1());
document.write("<br/>-------------------<br/>");

//2.while()循环
    function sum2() {
        var result2 = 0;
        var i = 1;
        while (i <= 100) {
            result2 += i;
            i++;
            
        }
        return result2
    }
    document.write(sum2());
document.write("<br/>-------------------<br/>");

//3.do-while语句
    function sum3() {
        var result3 = 0;
        var i = 1;
        do {
            result3 += i;
            i++;
        }
        while (i <= 100);

        return result3
    }
     document.write(sum3());
     document.write("<br/>-------------------<br/>");

<!DOCTYPE html> 
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            
        </style>
        <script>
        
        </script>
    </head>
    <body>
    </body>
</html>