JMeter functions are special values which can display fields of any sampler or any
JMeter test element within the test.
Syntax of a function in JMeter:
${__functionName(var1,var2,var3)}
Where function name is the name of the function followed by parameters in parenthesis. To add a function parameter with a comma then we must use it along with escape character "\", else JMeter will treat it as a parameter delimiter. Functions and variables in JMeter are case sensitive.
Below is a list of functions supported by JMeter .
Regular Expressions:
Regular expressions are used to search for a pattern in a test plan. Regular expression help in fetching useful information from the server response easily. A popular use case would be to fetch the value of session id from the server response using regular expression. Regular expression can be added to any component in a test plan. Regular expression is added to test plan via Regular expression extractor.
Add regular expression:
1)Right click on thread group → Add →Post Processor → Regular Expression Extractor.
2)From the view result tree:
