What is the use of "return 0" and what effects does it gives in the total output.

Answer 1

If you're talking about the main function(int main),It's optional(no effect) ,something that c++ inherited from c.

Answer 2

https://www.sololearn.com/learn/JavaScript/1148/?ref=app

Answer 3

Answers in this thread can help

https://www.sololearn.com/Discuss/220394/?ref=app

Answer 4

https://code.sololearn.com/cN0uCyB2LTa9/?ref=app
https://code.sololearn.com/chHAph306Ayh/?ref=app