console 命令行工具 X clear

console

window.onload=function(){
    

    document.body.innerHTML='<input id="btn" type="button" value="按钮"/><br/>';

    var i1=document.createElement("input");
    i1.id="btn";
    i1.type="button";
    i1.value="按钮";
    document.body.appendChild(i1);

}

<!DOCTYPE html> 
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        
    </head>
    <body>
    </body>
</html>