Which is the default return value of functions in C++?

Write a function in C++ that accepts a single number, calculates the number of positive odd numbers below the parameter value and returns the calculated result to the main method.

Write a value function in a C++ program that has two double parameters, calculates their difference, and returns the absolute value of the difference?

Create a function in C language that takes two integers x, and y as the parameters and returns the sum and the absolute difference of both the numbers but the return type of the function should be void. You can add extra parameters to the function but the function should not return anything and should send the required values as well. Test your function for the numbers 10, and 5 inside the main function.

List out all the valid variable names in C++ from all the variable names given below: _, $, 6t, t, v1 2, t#, mynum!, hello, break, v1_v2, num%, P2 Valid identifiers:

Write a function prototype for a function named my_function that accepts two integers (a,b) as parameters and returns a integer? (C++)