What can be the return type of a function in C?

The return type of a function in C can be any data type, including void. This means that a function can return values of types such as int, float, double, char, or even custom types like structs. Additionally, a function can also have a void return type, indicating that it does not return any value at all.

In C programming, specifying the return type is essential because it defines what type of value the function will produce when called. For instance, if a function is defined with a return type of int, it must return an integer value; if it's defined with a return type of float, it must return a floating-point number. Using a void return type is common for functions that perform operations but do not need to return any value to the caller.

The versatility in return types allows for greater flexibility and enables the creation of more complex programs. It is crucial for programmers to understand how return types work in order to effectively structure their functions according to the needs of the program they are developing.