Question

Mutator methods typically . . .

A) set instance data fields
B) retrieve instance data fields
C) retrieve static variables
D) set local variable

Answer 1

Mutator methods, also known as setters, are used to set instance data fields of an object in object-oriented programming, ensuring data encapsulation and integrity.

Step-by-step explanation:

Mutator methods in object-oriented programming are used to set instance data fields of an object. These methods are sometimes called 'setters' and they allow us to change the values of data fields after an object has been instantiated. The primary purpose of a mutator method is to control how important variables within an object are modified and to ensure data encapsulation and integrity.

For example, if we have a Car class with a private instance variable called speed, a mutator method might look like this:

public void setSpeed(int newSpeed) {
this.speed = newSpeed;
}

This method allows the speed of a car object to be set to a new value while adhering to any constraints or validation the method may implement. This contrasts with 'getter' methods (which retrieve values), methods that interact with static variables, or those that set local variables within a method's scope.