What will happen if you compile and run a function with no return type specified?

In programming languages such as C and C++, a function must have a specified return type to compile successfully. If a function is defined without a return type, the compiler does not have the information needed to understand what should be returned when the function is called. This lack of specification leads to a situation where the compiler raises a compilation error, indicating that it cannot complete the compilation process due to the absence of a defined return type.

In contrast, when functions are defined with return types (such as int, float, void, etc.), the compiler knows how to handle the returned value appropriately. If you were to compile and run such a function with no specified return type, the program would fail to compile entirely, preventing it from running at all. Thus, the correct understanding of the situation is that the absence of a return type results in a compilation error, halting the process before execution can even occur.