what is the use of return 0?

Answer 1

to tell compiler that program is executed successfully

Answer 2

it tells the compiler that program is successfully
executed if we write return 1 in place of return 0 then compiler will think that there will be abnormal execution and it will again check the code if there is some mistake if not OS cannot understand

Answer 3

no need of giving return 0 if u use int main() as main()

Answer 4

it tell the compiler that the program is executed without any error &successfully