// Comprueba si una cadena es json o no.
	// 19/01/2011 Jatubio - http://webfreak.no/wp/2007/09/07/jsontest-for-mootools/
function is_json($string)
{
	return !empty($string) && is_string($string) && preg_match('/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/',$string);
}

Check if a string it's json encoded using regular expressions

Thanks to Jens Anders Bakke for his mootools code published in webfreak.no

http://webfreak.no/wp/2007/09/07/jsontest-for-mootools/

Check if a string it's json encoded using regular expressions

json

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