一、JavaScript介绍
1.JavaScript是互联网上最流行的脚本语言,这门语言可用于web和HTML,更可广泛用于服务器、PC端、移动端。
2.JavaScript脚本语言:JavaScript是一种轻量级的编程语言。JavaScript是可插入HTML页面的编程代码。JavaScript插入HTML页面后,可由所有的浏览器执行。
二、JavaScript实现
1.JavaScript用法:HTML中的脚本必须位于<script></script>标签之间。脚本可被放置在HTML页面的<body>和<head>部分中。
2.JavaScript标签:在HTML中插入JavaScript,使用<script>标签。在<script></script>之间书写代码
3.JavaScript使用限制:在HTML中,不限制脚本数量。通常会把脚本放置于<head>标签中,以不干扰页面内容。
4.代码演示
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
<script>
document.write(
"hello yeleven"
);
</script>
</head>
<body>
</body>
</html>
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
</head>
<body>
<script>
document.write(
"hello yeleven"
);
</script>
</body>
</html>
|
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
</head>
<body>
<script>
document.write(
"hello yeleven"
);
</script>
<script>
document.write(
"hello yeleven"
);
</script>
</body>
</html>
|
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
</head>
<body>
<script src=
"myjs.js"
></script>
</body>
</html>
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三、JavaScript输出
1.JavaScript通常用来操作HTML
2.文档输出:document.write("<p>This is my first JavaScript</p>");
3.实例
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
</head>
<body>
<p id=
"pid"
>Hello</p>
<script>
document.getElementById(
"pid"
).innerHTML=
"yeleven"
;
</script>
</body>
</html>
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<!DOCTYPE html>
<html lang=
"en"
>
<head>
<meta charset=
"UTF-8"
>
<title>Title</title>
</head>
<body>
<script>
document.write(
"<h1>标签h1</h1>"
);
</script>
</body>
</html>
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本文转自yeleven 51CTO博客,原文链接:http://blog.51cto.com/11317783/1791501