console 命令行工具 X clear
console
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>1~100的和</title>
</head>
<body>
    <input type="button" value="计算" onclick="getSum()">
    <script>
        function getSum(){
            var i = 1, sum = 0;
            do{
                sum += i
                i++;
            }while(i<=100)
            console.log('1到100个数相加的结果为：' + sum)
        }
         
        
    </script>
</body>
</html>