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Re: FAQ Topic - How do I trim whitespace? (2011-10-14)

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In comp.lang.javascript message <j7824g$6lf$1@speranza.aioe.org>, Thu,
13 Oct 2011 22:09:37, J.R. <groups_jr-1@yahoo.com.br> posted:

>On 13/10/2011 20:00, FAQ server wrote:
>> -----------------------------------------------------------------------
>> FAQ Topic - How do I trim whitespace?
>> -----------------------------------------------------------------------
>>
>> ECMAScript 5 defines `String.prototype.trim`. Where not supported,
>> it can be added as a function that uses a regular expression:
>>
>> if(!String.prototype.trim) {
>> String.prototype.trim = function() {
>> return String(this).replace(/^\s+|\s+$/g, "");
>> };
>> }
>
>> The complete comp.lang.javascript FAQ is at
>> http://jibbering.com/faq/
>>
>
>A few months ago, there was an article at Jibbering,com with a
>different version of this code:
>
>  /** @see http://jibbering.com/faq/#trimString */
>  if (typeof String.prototype.trim !== "function") {
>    String.prototype.trim = function () {
>      // return String(this).replace(/^\s+|\s+$/g, "");
>      return this.replace(/^\s+|\s+$/g, "");
>    };
>  }
>
>I think that is more consistent with ECMA-262 5th ed., 15.5.4.20.


If, before that latter code is executed, String.prototype.trim exists
and is not a function, then it would be better to leave it as it is; a
subsequent attempt to use it as a function will then give an error
message in testing.

In the former code, it would be better to explicitly test against
"undefined".  The cost in execution time will be unimportant; the saving
in time taken to understand may be significant, remembering that the
true expert will not use the FAQ code, having already written what he
needs.

-- 
 (c) John Stockton, Surrey, UK.  ?@merlyn.demon.co.uk   Turnpike v6.05   MIME.
   Web  <http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
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FAQ Topic - How do I trim whitespace? (2011-10-14) "FAQ server" <javascript@dotinternet.be> - 2011-10-13 23:00 +0000
  Re: FAQ Topic - How do I trim whitespace? (2011-10-14) "J.R." <groups_jr-1@yahoo.com.br> - 2011-10-13 22:09 -0300
    Re: FAQ Topic - How do I trim whitespace? (2011-10-14) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-14 20:54 +0200
    Re: FAQ Topic - How do I trim whitespace? (2011-10-14) Dr J R Stockton <reply1141@merlyn.demon.co.uk> - 2011-10-15 19:17 +0100

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