Why use getters and setters c

The getters and setters are usually public and the variables are made private. A mutator is a member function that allows for editing of the contents of a protected data member. For a mutator to accomplish its function , the following conditions must be present: 1 As a parameter, it must have the value to be assigned to the data member. Access functions typically come in two flavors: getters and setters.

Getters also sometimes called accessors are functions that return the value of a private member variable. Setters also sometimes called mutators are functions that set the value of a private member variable.

They are used instead of making a class member variable public and changing it directly within an object. To access a private object member, an accessor function must be called.

A getter is a deposit of reactive material that is placed inside a vacuum system, for the purpose of completing and maintaining the vacuum. When gas molecules strike the getter material, they combine with it chemically or by absorption. Thus the getter removes small amounts of gas from the evacuated space. Data encapsulation led to the important OOP concept of data hiding. A constructor is a member function of a class which initializes objects of a class. It is special member function of the class.

An accessor is a class method used to read data members, while a mutator is a class method used to change data members. These two keywords define accessor functions: a getter and a setter for the fullName property. This is much better than updating the number variable directly:.

If you update number directly, it's possible that you'll cause unintended side effects somewhere else in your code. Here, setting number to 13 violates the 1 to 10 constraint we want to establish. Making number a private variable and using the setNumber method would prevent this from happening. On the other hand, the only way to read the value of number is by using a getter method:.

If this article was helpful, tweet it. Learn to code for free. Our object-oriented programs can meet these data setting and data retrieval needs by providing getter and setter member functions as part of the class interface. This class will have two member variables — name and age.

The function needs to check the age passed in as the argument to make sure it is greater than or equal to 0 and less than or equal to Here is the definition for a setAge function:. Just add this definition to the class definition. The output from this program is:. We need the data validation of this function in the constructor as well.

For consistency purposes, we should add this function to our constructor also, like this:. Getter functions are easier to define as they just need to retrieve the data stored in a class object. Here are the getter functions for the Person class:. Here is the complete Person class definition with all the getter and setter functions included:.

Getter and setter functions are an important addition to the class interface. Since the member variables of a class will be marked as private, the users of your class will need some means of retrieving and setting their values. Getter and setter functions provide this access in a safe manner, since setter functions can be written with data validation code included to make sure that member variables are set to valid values.