JavaScript字符串对象(string)基本用法示例

时间:2020-05-15 books1958 人气:0

本文实例讲述了JavaScript字符串对象(string)基本用法。分享给大家供大家参考，具体如下：

1.获取字符串的长度：

var s = "Hello world";
document.write("length:"+s.length);

2.为字符串添加各种样式，如：

var txt = "Some words";
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>Link: " + txt.link("//www.qb5200.com") + "</p>")

3.获取字符串中部分内容首次出现的位置：

var hw_text = "Hello world";
document.write(hw_text.indexOf("Hello")+"<br/>");
document.write(hw_text.indexOf("world")+"<br/>");
document.write(hw_text.indexOf("abc")+"<br/>");

4.内容替换：

var str="Visit Microsoft!"
document.write(str.replace(/Microsoft/,"W3School"))

效果图：

示例代码：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="Content-Language" content="zh-cn" />
<title>Javascript 字符串对象</title>
<head>
 <style>
  body {background-color:#e6e6e6}
 </style>
</head>
<body>
 <h3>（一）length属性：获取字符串的长度</h3>
 <p id="hw">Hello world, Hello javascript!</p>
 <script>
  var s = document.getElementById("hw").innerHTML;
  document.write("length:"+s.length);
 </script>
 <h3>（二）为字符串添加样式</h3>
 <p>对字符串调用样式的相关方法时，会自动拼接相应的html标签</p>
 <p id = "hw_02">some words</p>
 <button onclick="alertBig()">Call txt.big()</button>
 <script>
  var txt = document.getElementById("hw_02").innerHTML;
  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>Link: " + txt.link("//www.qb5200.com") + "</p>")
  function alertBig(){
   alert(txt.big());
  }
 </script>
 <h3>（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</h3>
 <script>
  var hw_text = "Hello world";
  document.write(hw_text.indexOf("Hello")+"<br/>");
  document.write(hw_text.indexOf("world")+"<br/>");
  document.write(hw_text.indexOf("abc")+"<br/>");
 </script>
 <h3>（四）replace()方法：替换字符串中的部分内容</h3>
 <script>
  var str="Visit Microsoft!"
  document.write(str.replace(/Microsoft/,"jb51"))
 </script>
</body>
</html>

希望本文所述对大家JavaScript程序设计有所帮助。

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