Description of comprehensive application based on java enumeration class

Author：Eve Cole Update Time：2024-11-24 09:12:01

The following code takes a traffic light as an example:

Copy the code code as follows:

public class Test {

public static void main(String[] args) {
Trafficlight light = Trafficlight.RED;

System.out.println(light.time);
System.out.println(light.nextLigth());
// The ordinal() method returns the order in which the enumeration is declared
System.out.println(light.ordinal());
// The values() method gets an array of all enumeration types
for(Trafficlight light1:light.values()){
System.out.println(light1.name());
}

// The valueOf() method can convert the string into the corresponding enumeration object
System.out.println(light.RED ==light.valueOf("RED"));
}

public enum Trafficlight {
GREEN(30) {

@Override
public Trafficlight nextLigth() {
return RED;
}
},
RED(30) {

@Override
public Trafficlight nextLigth() {
return YELLOW;
}
},
YELLOW(10) {

@Override
public Trafficlight nextLigth() {
return GREEN;
}
};
public abstract Trafficlight nextLigth();

private int time;

//Constructor
private Trafficlight(int time) {
this.time = time;
}

public int getTime(){
return time;
}

}

In the code, you can see that GREEN, RED, and YELLOW are respectively a subclass of Trafficlight and serve as its member variables. There is an abstract method nextLight() in Trafficlight, which must be implemented in the subclass, so @Override. In addition, they also inherit the method of the parent class, so the method getTiime() of the parent class can be called. Since the parent class Trafficlight Declaring a constructor with parameters overrides a constructor without parameters, so parameters must also be added when building a subclass.

In the code, light is just equivalent to an instance of the parent class. You can use it to get the subclasses of each member variable and call various methods. The valueOf(String) method can convert a string into an enumeration.