exercise-your-skill

list of url for exercise our skill

https://www.codewars.com/

https://www.hackerrank.com

http://exercism.io/

https://projecteuler.net

http://www.codeabbey.com

https://checkio.org

https://leetcode.com

https://www.codingame.com/home

mooc

https://www.codecademy.com