JavaScript中字符串(String)对象
String 对象用于处理已有的字符块。
第一：计算字符串长度(length)
举例如下：
<html>
<body>
<script type="text/javascript">
var txt="Hello World!";
document.write(txt.length);
</script>
</body>
</html>
输出：12<body>
<script type="text/javascript">
var txt="Hello World!";
document.write(txt.length);
</script>
</body>
</html>
第二：为字符串添加样式
举例如下：
<html>
<body>
<script type="text/javascript">
var txt="Hello World!"
document.write("<p>Big: " + txt.big() + "</p>")
document.write("<p>Small: " + txt.small() + "</p>")
document.write("<p>Bold: " + txt.bold() + "</p>")
document.write("<p>Italic: " + txt.italics() + "</p>")
document.write("<p>Blink: " + txt.blink() + " (does not work in IE)</p>")
document.write("<p>Fixed: " + txt.fixed() + "</p>")
document.write("<p>Strike: " + txt.strike() + "</p>")
document.write("<p>Fontcolor: " + txt.fontcolor("Red") + "</p>")
document.write("<p>Fontsize: " + txt.fontsize(16) + "</p>")
document.write("<p>Lowercase: " + txt.toLowerCase() + "</p>")
document.write("<p>Uppercase: " + txt.toUpperCase() + "</p>")
document.write("<p>Subscript: " + txt.sub() + "</p>")
document.write("<p>Superscript: " + txt.sup() + "</p>")
document.write("<p>Link: " + txt.link(http://codeshark.cnblogs.com) + "</p>")
</script>
</body>
</html>
第三：indexOf()方法：定位字符串中某一个指定的字符首次出现的位置。<body>
<script type="text/javascript">
var txt="Hello World!"
document.write("<p>Big: " + txt.big() + "</p>")
document.write("<p>Small: " + txt.small() + "</p>")
document.write("<p>Bold: " + txt.bold() + "</p>")
document.write("<p>Italic: " + txt.italics() + "</p>")
document.write("<p>Blink: " + txt.blink() + " (does not work in IE)</p>")
document.write("<p>Fixed: " + txt.fixed() + "</p>")
document.write("<p>Strike: " + txt.strike() + "</p>")
document.write("<p>Fontcolor: " + txt.fontcolor("Red") + "</p>")
document.write("<p>Fontsize: " + txt.fontsize(16) + "</p>")
document.write("<p>Lowercase: " + txt.toLowerCase() + "</p>")
document.write("<p>Uppercase: " + txt.toUpperCase() + "</p>")
document.write("<p>Subscript: " + txt.sub() + "</p>")
document.write("<p>Superscript: " + txt.sup() + "</p>")
document.write("<p>Link: " + txt.link(http://codeshark.cnblogs.com) + "</p>")
</script>
</body>
</html>
举例如下：
<html>
<body>
<script type="text/javascript">
var str="Hello world!";
document.write(str.indexOf("Hello") + "<br />");
document.write(str.indexOf("World") + "<br />");
document.write(str.indexOf("world"));
</script>
</body>
</html>
输出结果为：<body>
<script type="text/javascript">
var str="Hello world!";
document.write(str.indexOf("Hello") + "<br />");
document.write(str.indexOf("World") + "<br />");
document.write(str.indexOf("world"));
</script>
</body>
</html>
0
-1
6
第四：match()方法：查找字符串中特定的字符，并且如果找到的话，则返回这个字符。否则返回null.
举例如下：
<html>
<body>
<script type="text/javascript">
var str="Hello world!";
document.write(str.match("world") + "<br />");
document.write(str.match("World") + "<br />");
document.write(str.match("worlld") + "<br />");
document.write(str.match("world!"))
</script>
</body>
</html>
结果如下：<body>
<script type="text/javascript">
var str="Hello world!";
document.write(str.match("world") + "<br />");
document.write(str.match("World") + "<br />");
document.write(str.match("worlld") + "<br />");
document.write(str.match("world!"))
</script>
</body>
</html>
world
null
null
world!
第五：replace()方法：在字符串中用某些字符替换另一些字符。
<html>
<body>
<script type="text/javascript">
var str="Visit Microsoft!";
document.write(str.replace(/Microsoft/,"cnBlogs"));
</script>
</body>
</html>
<body>
<script type="text/javascript">
var str="Visit Microsoft!";
document.write(str.replace(/Microsoft/,"cnBlogs"));
</script>
</body>
</html>
