regex to extract HTML attribute value

Question

I have the following HTML

TO :

        

Answer 1

Using JMeter, use Regular Expression Extractor to achieve this task.

Reference Name: mynum
Regular Expression: value="(.+?)"
Template: $1$
Match No.: 1

If you specify using a Match No:, the rules are as follows:

0 = Random Match
1 = First Match 
2 = Second Match
etc....

And then you can use the corresponding variable to access the match. ${mynum_1}