https://www.codecademy.com/

https://www.tutorialspoint.com/tutorialslibrary.htm

For Matlab

https://uk.mathworks.com/support/learn-with-matlab-tutorials.html

For C++

http://www.cplusplus.com/doc/tutorial/

For Java

http://www.java2s.com/Tutorial/Java/CatalogJava.htm

For CUDA

http://www.nvidia.com/object/cuda_home_new.html

Good work :)

Here are some of the other sites which you could look into. 

Happy Coding.

https://www.entrepreneur.com/article/250323

https://www.youtube.com/playlist?list=PLGLfVvz_LVvSX7fVd4OUFp_ODd86H0ZIY

https://www.mooc-list.com/tags/programming

https://www.class-central.com/search?q=Programming

try any beginner level course from coursera or udacity

https://www.coursera.org/

https://in.udacity.com/

I prefer Codecademy since it is interactive which makes it easier and fun. You can learn Python, HTML and CSS, JavaScript and others

You could also learn through MOOCs

In Fun platform (https://www.fun-mooc.fr/cours/#filter/subject/informatique?page=1&rpp=50)

Here you can see many MOOCs about programming: C, C++, Java, Python, ...

They have good bedagogical approaches ...

https://www.fun-mooc.fr/cours/#filter/subject/informatique?page=1&rpp=50

Try any of these

https://www.edx.org/

https://in.udacity.com/

https://www.coursera.org/

https://www.codecademy.com/learn

http://www.w3schools.in/

Hi, friend. Here is some links. Good studies !

https://developer.mozilla.org

http://www.w3schools.com/

Communities:

https://www.reddit.com/r/learnjavascript/

https://www.reddit.com/r/javascript/

http://stackoverflow.com/questions/tagged/javascript

https://plus.google.com/communities/100875929141897651837

Dear dude here are useful links.

https://www.khanacademy.org/

https://mva.microsoft.com/

http://www.w3schools.com/

try these:

www.edx.org

https://www.reddit.com/r/javascript/

Another one: https://www.udemy.com/matlab-programming-mxc/

Thank you, Professor Michael X Cohen.

Best regards,

Ivan K. Singgih