Final answer:
Modification methods, or mutator methods, often have a void return type because their purpose is to alter the state of an object without returning any value. Accessor methods, on the other hand, retrieve data and therefore usually return a value corresponding to the data being accessed.
Step-by-step explanation:
Modification methods, also known as mutator methods, often have a void return type. They are designed to change the state of an object without the need to return a value. For example, the setter methods in a class are mutators since they typically set the value of a private field and do not return any value (void return type).
On the other hand, accessor methods, such as getters, are designed to retrieve data from an object but not to modify it. Therefore, these methods usually return a value that represents the data being accessed, such as an integer, string, or object, based on the field they are accessing.
The usage of void in mutator methods is appropriate because the primary purpose is to modify the internal state of the object. As long as the state has been updated as intended, there's no value that needs to be returned to the caller.