You can add states and behaviors to enum constants by defining instance variables and methods in an enum. All of these are accessible by the enum constants. Let's modify the Size enum defined in the previous section, by adding a state and behavior to it. Each enum constant can define a constant, specific class body, define a new state and behavior, or override the default behavior of the enum methods in which it is defined. The following is an example of this:

enum Size { 
    SMALL(36, 19), 
    MEDIUM(32, 20) {               // Constant specific class body  
        int number = 10;                    // variable specific to 
                                            //MEDIUM 
        int getSize() {                     // method specific to 
                                            //MEDIUM 
            return length + width; 
        } 
    }, 
    LARGE(34, 22) { 
        @Override  
        public String toText() {            // overriding method toText 
                                            //for  
            return "LARGE";                 // constant LARGE 
        } 
    }; 
 
    int length;                             // instance variable 
                                            //accessible 
    int width;                              // to all enum constants 
 
    Size(int length, int width) {           // enum constructor; 
                                            //accepts length 
        this.length = length;               // and width 
        this.width = width; 
    } 
 
    int getLength() {                       // method accessible to all 
                                            //enum 
        return length;                      // constants 
    } 
 
    int getWidth() {                        // method accessible to all 
                                            //enum 
        return width;                       // constants 
    }  
 
    public String toText() {               // method accessible to all 
                                           //enum 
        return length + " X " + width;     // constants 
    } 
} 

In the preceding example, the Size enum defines three enum constants—SMALL, MEDIUM, and LARGE. It also defines instance variables (length and breadth), a constructor, and the getLength(), getWidth, and toText() methods.