html - 首次加载 html 页面时默认打开导航栏

Question

如何修改此代码以在页面首次加载时保持侧边导航栏打开？我希望我的侧边导航栏默认打开。

function openNav() {
  document.getElementById("mySidenav").style.width = "250px";
  document.getElementById("main").style.marginLeft = "250px";
  document.body.style.backgroundColor = "rgba(0,0,0,0.4)";
}

function closeNav() {
  document.getElementById("mySidenav").style.width = "0";
  document.getElementById("main").style.marginLeft = "0";
  document.body.style.backgroundColor = "white";
}

<div id="wrapper">
  <header>
    <div></div>
  </header>
  <nav>
    <span style="font-size:30px;cursor:pointer" onclick="openNav()">&#9776; Learn Here</span>

    <div id="mySidenav" class="sidenav">
      <img src="https://cloud.netlifyusercontent.com/assets/344dbf88-fdf9-42bb-adb4-46f01eedd629/68dd54ca-60cf-4ef7-898b-26d7cbe48ec7/10-dithering-opt.jpg" height="20%" width="70%" style="padding-left: 36px; padding-right: 36px">
      <a href="javascript:void(0)" class="closebtn" onclick="closeNav()">&times;</a>
      <a class="nav_padding" href="#">About me</a>
      <a class="nav_padding" href="#">Resume</a>
      <a class="nav_padding" href="#">Projects</a>
      <a class="nav_padding" href="#">Contact Me</a>
      <script>
      </script>
    </div>
  </nav>
</div>

Answer 1

在 $(document).ready(function(){ }) 上添加脚本；ready 函数在页面加载时执行 java 脚本，

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<script>
$(document).ready(function(){
document.getElementById("mySidenav").style.width = "250px";
            document.getElementById("main").style.marginLeft = "250px";
            document.body.style.backgroundColor = "rgba(0,0,0,0.4)";
});
</script>