JS go to string before and after space 5 kinds of realization method and compare _javascript skill

If we write to register in the project, the user enters the space, how can we eliminate the space?
Here is the JS I often use to share with you under:

First: cyclic check replacement
[JavaScript]

Copy Code code as follows:

For consumer calls
function Trim (s) {
Return TrimRight (Trimleft (s));
}
Remove the left blank
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;
}
Remove the blank www.jb51.net on the right
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;
}

Second: Regular replacement
[JavaScript]

Copy Code code as follows:

<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>

Third: Using jquery
[JavaScript]

Copy Code code as follows:

$.trim (str)

The internal implementation of jquery is:
[JavaScript]

Copy Code code as follows:

function Trim (str) {
Return Str.replace (/^ (\s|\u00a0) +/, ""). Replace (/(\S|\U00A0) +$/, "");
}

Fourth: Use of Motools
[JavaScript]

Copy Code code as follows:

function Trim (str) {
Return Str.replace (/^ (\s|\xa0) +| ( \S|\XA0) +$/g, "");
}

type Fifth: cropping string mode
[JavaScript]

Copy Code code as follows:

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;
}

Test Fifth method is most efficient at processing long strings。

Copy Code code as follows:

<script type= "Text/javascript" >
Remove Space
function Systemtrim (str) {
var regExp =/(^\s*) | (\s*$)/;
Return Str.replace (RegExp, "");
}
Call
function Add ()
{
var Ownername=document.form1.ownername.value;
if (Systemtrim (ownername) = "")
{
Alert ("Please enter your name!") ");
Return
}
}
<script>