转载于:http://www.cnblogs.com/mingforyou/p/3930638.html
第一种：循环检查替换
//供使用者调用 ?function trim(s){ ?????return trimRight(trimLeft(s)); ?} ?//去掉左边的空白 ?function trimLeft(s){ ?????if(s == null) { ?????????return ""; ?????} ?????var whitespace = new String(" \t\n\r"); ?????var str = new String(s); ?????if (whitespace.indexOf(str.charAt(0)) != -1) { ?????????var j=0, i = str.length; ?????????while (j < i && whitespace.indexOf(str.charAt(j)) != -1){ ?????????????j++; ?????????} ?????????str = str.substring(j, i); ?????} ?????return str; ?} ?//去掉右边的空白 www.2cto.com ??function trimRight(s){ ?????if(s == null) return ""; ?????var whitespace = new String(" \t\n\r"); ?????var str = new String(s); ?????if (whitespace.indexOf(str.charAt(str.length-1)) != -1){ ?????????var i = str.length - 1; ?????????while (i >= 0 && whitespace.indexOf(str.charAt(i)) != -1){ ????????????i--; ?????????} ?????????str = str.substring(0, i+1); ?????} ?????return str; ?} ????????
第二种：正则替换
<SCRIPT LANGUAGE="JavaScript"> ?<!-- ?String.prototype.Trim = function() ?{ ?return this.replace(/(^\s*)|(\s*$)/g, ""); ?} ?String.prototype.LTrim = function() ?{ ?return this.replace(/(^\s*)/g, ""); ?} ?String.prototype.RTrim = function() ?{ ?return this.replace(/(\s*$)/g, ""); ?} ?//--> ?</SCRIPT> //去左空格;function ltrim(s){ ???return s.replace(/(^\s*)/g, "");}//去右空格;function rtrim(s){ ???return s.replace(/(\s*$)/g, "");}//去左右空格;function trim(s){ ???return s.replace(/(^\s*)|(\s*$)/g, "");}
第三种：使用jquery
$.trim(str)
jquery内部实现为：
function trim(str){ ??????return str.replace(/^(\s|\u00A0)+/,‘‘).replace(/(\s|\u00A0)+$/,‘‘); ??}
第四种：使用motools
function trim(str){ ??????return str.replace(/^(\s|\xA0)+|(\s|\xA0)+$/g, ‘‘); ??} ?
第五种：裁剪字符串方式
function trim(str){ ??????str = str.replace(/^(\s|\u00A0)+/,‘‘); ??????for(var i=str.length-1; i>=0; i--){ ??????????if(/\S/.test(str.charAt(i))){ ??????????????str = str.substring(0, i+1); ??????????????break; ??????????} ??????} ??????return str; ??} ?//----------------------------------------------------------// ????去掉字符串前后的空格// ???返回值：// ???去除空格后的字符串//----------------------------------------------------------function trim(param) { ???if ((vRet = param) == ‘‘) { return vRet; } ???while (true) { ???????if (vRet.indexOf (‘ ‘) == 0) { ???????????vRet = vRet.substring(1, parseInt(vRet.length)); ???????} else if ((parseInt(vRet.length) != 0) && (vRet.lastIndexOf (‘ ‘) == parseInt(vRet.length) - 1)) { ???????????vRet = vRet.substring(0, parseInt(vRet.length) - 1); ???????} else { ???????????return vRet; ???????} ???}}js 去除空格
原文地址：http://www.cnblogs.com/leilei-1/p/7788167.html