In this article we are going to see how we can use regular expression with a function to retrieve information from response data. We will see full detail of the function.

${__regexFunction((?i).*?abcd.*,$2$,ALL,,,ReturnOnNoMatch,myVariable,InputVariableTextToParse)}

This is the function with Seven Parameters.

First Parameter(mandatory) :The regular expression which will be applied to response data. It grabs all the matches.

Second Parameter(mandatory) : This is the template string that will replace the function at run-time. To refer to a group captured , we need to use the syntax: $[group_number]$. Ie: $1$, or $2$.

Third Parameter : We have to insert our choice of matching in here for the use in case of multiple matches.We can choose in 4 ways.
An integer - Tells JMeter to use that match. '1' for the first found match, '2' for the second, and so on
RAND - Tells JMeter to choose a match at random.
ALL - Tells JMeter to use all matches, and create a template string for each one and then append them all together.
A float number between 0 and 1 - tells JMeter to find the Xth match using the formula: (number_of_matches_found * float_number) rounded to nearest integer

Fourth Parameter : If ALL selected from 3rd, this argument item(character/string) will be added between every value during append

Fifth Parameter :  Default returning value if no match found

Sixth Parameter : A reference name for reusing the values parsed by this function. Stored values are ${myVer}  and ${myVer_g#} where "#" is the group number from the regular expression ("0" can be used to refer to the entire match).

Seventh Parameter :  Input variable name. If specified, then the value of the variable is used as the input instead of using the previous sample result.

-It can also store variable for further use
-As it can use reference variable, we can use previous results as parameters.
-Vastly used for quick data and report processing.

Thanks..:)