what is the use

Dear all,
can anyone please tell me what this do:
var items = DataItems.replace("(?m)^[ \t]*\r?\n", "");

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ethar1Asked:
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kaufmed   ( ⚆ _ ⚆ )Patches? We Ain't Got No Patches! We Don't Need No Patches! I Don't Have to Push You No Stinkin' Patches!Commented:
It replaces any number ( * )--including zero--of spaces and tabs ( [ \t] ) found just before a newline character ( \n ) with an empty string ( "" ). The newline may be optionally ( ? ) preceded by a carriage return ( \r ).

This is what is known as a regular expression. The replace method accepts such as a parameter. You can read more at www.regular-expressions.info.
dimmergeekCommented:
I'm  not too great with regexes, but I believe this will replace all tabs and newlines with and empty character string ("").  The (?m) tells the regex to match at all line breaks
kaufmed   ( ⚆ _ ⚆ )Patches? We Ain't Got No Patches! We Don't Need No Patches! I Don't Have to Push You No Stinkin' Patches!Commented:
but I believe this will replace all tabs and newlines
It will match all tabs (and spaces) that occur immediately before a newline, not simply all tabs (and spaces). To say that all newlines will be replaced is accurate.

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ethar1Author Commented:
dear all,
could you please continue answer the question :
http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/Q_28325842.html
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