高手就能够直接跳过了，刚開始学习javascript,从零開始， 记录一点一滴，不断提高。

菜鸟的不断成长。

以下就写上几个简单的JS  入门代码吧。高手就不要BS了

<!DOCTYPE html>
<html>

  <body>
    <script>
    function changeImage(){
      element=document.getElementById("myimage")
      if(element.src.match("bulbon")){
        element.src="i/eg_bulboff.gif";
      }else{
        element.src="i/eg_bulbon.gif";
      }
    }
    </script>

    <img id="myimage" onclick="changeImage()" src="i/eg_bulboff.gif" />

  </body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
  <h1>Jscript样例1</h1>
  <p id="demo">
  hello world.welcome to here.
  </p>
<script type="text/javascript">
    function myf(){
    x=document.getElementById("demo");
    x.innerHTML="你好，PPKER。欢迎来到JS";
    }
</script>
  <input type="button" onclick="myf()" value="点击">
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
  <h1>改变样式</h1>
  <p id="demo">
  德玛上单，不给就送啊！
  </p>
  <script type="text/javascript">
    function myf(){
      x=document.getElementById("demo");
      x.style.color="red";
    }
  </script>
  <input type="button" onclick="myf()" value="点击">
</body>
</html>
<!DOCTYPE html>
<html>
<head><meta charset="utf-8" /></head>
<body>
<input id="demo" type="text">
<script type="text/javascript">
function myf()
{
var x=document.getElementById("demo").value;
if(x==""||isNaN(x))
  {
  alert("姐，请输入数字");
  }else{
    alert("OK");
  }
}
</script>

<button type="button" onclick="myf()">点击这里</button>

</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
  function  myf(){
    document.getElementById("demo").innerHTML="~~~上MISS了，嘿嘿嘿";
  }
</script>
</head>
<body>
  <p id="demo">努克萨斯</p>
  <button type="button" onclick="myf()">点击</button>
</body>
</html>

高手就不要BS了，都是从菜鸟開始的。别总是在想怎样学好，坚持下去吧。无他，唯孰而已。