How to debug jmeter script

There are different way to debug jmeter script. You can use following Postprocessor
 1. Debug PostProcesssor
    - You need to add as child in every sampler (e.g HTTP Request)
- Check value of variable in View Result Tree > Sampler's output

 2. BeanShell Postprocessor
   - You can log the variable value in jmeter.log file
     e.g ${__log("-Counter value-------------${counter} --------------")};

 3. You can user PostProcesssor > Regular Expression Extractor to check regex and its output

 4. Response Assertion :- We can use it to check both things. 1. Verify response and any specific Pattern by giving different rules