<script>
String.prototype.trim= function()
{
// 用正則表達式將前後空格
// 用空字符串替代。
return this.replace(/(^/s*)|(/s*$)/g, "");
}
// 有空格的字符串
var s = " leading and trailing spaces ";
// 顯示 " leading and trailing spaces (35)"
window.alert(s + " (" + s.length + ")");
// 刪除前後空格
s = s.trim();
// 顯示"leading and trailing spaces (27)"
window.alert(s + " (" + s.length + ")");