<head>
<title>Trim Example</title>
<script type="text/javascript">
String.prototype.trim = function () {
//使用.*?量词忽略优先
var reExtraSpace = /^\s*(.*?)\s*$/;
return this.replace(reExtraSpace, "$1");
};
function showText() {
var oInput1 = document.getElementById("txt1");
var oInput2 = document.getElementById("txt2");
oInput2.value = oInput1.value.trim();
}
</script>
</head>
<body>
<p>Enter some text containing leading and trailing spaces below and click the button<br />
<textarea rows="10" cols="50" id="txt1"></textarea><br />
<input type="button" value="Trim" onclick="showText()" /></p>
<p>Trimmed Text:<br />
<textarea rows="10" cols="50" id="txt2"></textarea></p>
</body>
</html>