10.2 Setters and Getters

It is generally considered a good idea to use methods to access a class variable. Set methods are used to store a value in a variable, get methods are used to retrieve them. These methods are very easy to create, but will protect against mistakes when your classes become more complex.

For consistency, I recommend you use the following rules to write these methods:

• The name of the method is equal to the name of the variable, preceded by set or get. (And with camelCaps of course)
• The method alters the value with the same name as the method.
• The set method has an argument of the same type as the value. It returns a reference to the class.
• The get method returns a variable with the same type as the class variable.

Here’s an example of a score class with set and get methods for an integer variable called ’points’.

 
class score { 
  int points; 
 
  int  getPoints(         ) { return points ; } 
5  void setPoints(int value) { points = value; } 
}
 

Another way to implement setters and getters would be to use a special symbol in the variable name. Most programmers use an underscore. This approach has the added bonus that there is a clear distinction between class variables and local variables, because all class variables start with an underscore.

 
class score { 
  int _points; 
 
  int  points(         ) { return _points ; } 
5  void points(int value) { _points = value; } 
}