How to check Environment Variables through Command Prompt

There are couple of ways which we could opt to check the environment variables through command prompt and details for the same is given below:-
(1) In Windows >> Command-Prompt, the command is :- echo %PATH%
(2) To get a list of all environment variables enter the command :- set
(3) To send those variables to a text file enter the command :- set > myFilename.txt