<! DOCTYPE HTML>
<HTML>
<head>
<Meta charset = "UTF-. 8">
<title> novice tutorial (runoob.com) </ title>
</ head>
<body>
<P>
the JavaScript capable of directly writing HTML output stream:
</ P>
<Script>
document.write ( "<h1 of> this is a header </ h1 of>" );
document.write ( "<P> this is a paragraph </ P>." ) ;
</ Script>
<P>
You can use only HTML output stream <strong> document.write </ strong>
. If you use it after the document has loaded (for example, in a function), will cover the entire document.
</ P>
</ body>
</ HTML>
<! DOCTYPE HTML>
<HTML>
<head>
<Meta charset = "GBK">
<title> newbie tutorial (runoob.com) </ title>
</ head>
<body>
<h1> My first JavaScript < / h1>
<the p->
JavaScript can react to events. For example, a click on the button:
</ the p->
<the Button of the type = "the Button" onclick = "Alert ( 'Welcome!')"> Point I </ the Button>!
</ Body>
</ HTML>
<! DOCTYPE HTML>
<HTML>
<head>
<Meta charset = "UTF-8">
<title> newbie tutorial (runoob.com) </ title>
</ head>
<body>
<h1> my first paragraph the JavaScript </ h1 of>
<P ID = "Demo">
the JavaScript to change the content of the HTML element.
</ P>
<Script> function myFunction ()
{
X = document.getElementById ( "Demo"); // find the elements
x.innerHTML = "the JavaScript the Hello!"; // change the content }
</ Script>
<Button type = "button" onclick = "myFunction ( )"> click here </ Button>
</ body>
<
<!DOCTYPE html>
<html>
<head>
<meta charset="gbk">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<script>
function changeImage()
{
element=document.getElementById('myimage')
if (element.src.match("bulbon"))
{
element.src="E:/72.jpg";
}
else
{
element.src="E:/0.jpg";
}
}
</script>
<img id="myimage" onclick="changeImage()" src="E:/72.jpg" width="100" height="180">
<p>点击切换鲜花</p>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<h1>我的第一段 JavaScript</h1>
<p id="demo">
JavaScript 能改变 HTML 元素的样式。
</p>
<script>
function myFunction()
{
x=document.getElementById("demo") // 找到元素
x.style.color="#ff0000"; // 改变样式
}
</script>
<button type="button" onclick="myFunction()">点击这里</button>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<h1>我的第一段 JavaScript</h1>
<p>请输入数字。如果输入值不是数字，浏览器会弹出提示框。</p>
<input id="demo" type="text">
<script>
function myFunction()
{
var x=document.getElementById("demo").value;
if(x==""||isNaN(x))
{
alert("不是数字");
}
}
</script>
<button type="button" onclick="myFunction()">点击这里</button>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<h1>我的第一段 JavaScript</h1>
<p>请输入数字。如果输入值不是数字，浏览器会弹出提示框。</p>
<input id="demo" type="text">
<script>
function myFunction()
{
var x=document.getElementById("demo").value;
if(isNaN(x)||x.replace(/(^\s*)|(\s*$)/g,"")==""){
alert("不是数字");
}
}
</script>
<button type="button" onclick="myFunction()">点击这里</button>
</body>
</html>
