//can we change the name of "add" function to "sum"?? -->ans. yes, we can but it will have to be replaced at all the places in the entire program //can we change the name of "add" function to "+"??

//the unexpected output is because the first one i.e the one without "int" is always thought to be pre-increment by the compiler and //the second one with "int" as argument is thought to be ...