17 Enum in Java ?

Example:

1. Define enum tên named Day

public enum Day {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY
}

2. Use Enum in Java class

public class EnumExample {
public static void main(String[] args) {
Day today = Day.MONDAY;

switch (today) {
case MONDAY:
System.out.println(“Today is Monday!”);
break;
case TUESDAY:
System.out.println(“Today is Tuesday!”);
break;
case WEDNESDAY:
System.out.println(“Today is Wednesday!”);
break;
case THURSDAY:
System.out.println(“Today is Thursday!”);
break;
case FRIDAY:
System.out.println(“Today is Friday!”);
break;
case SATURDAY:
System.out.println(“Today is Saturday!”);
break;
case SUNDAY:
System.out.println(“Today is Sunday!”);
break;
}
}
}

3. Enum with methods and fields

Enums can also contain fields, methods, and constructors just like regular classes

public enum Day {
SUNDAY(“Sunday”),
MONDAY(“Monday”),
TUESDAY(“Tuesday”),
WEDNESDAY(“Wednesday”),
THURSDAY(“Thursday”),
FRIDAY(“Friday”),
SATURDAY(“Saturday”);

private String dayName;

// Constructor cho enum
Day(String dayName) {
this.dayName = dayName;
}

// Phương thức getter để lấy tên ngày
public String getDayName() {
return dayName;
}
}

public class EnumExample {
public static void main(String[] args) {
Day today = Day.MONDAY;

System.out.println(“Today is ” + today.getDayName());

// Lặp qua tất cả các giá trị enum
for (Day day : Day.values()) {
System.out.println(day + “: ” + day.getDayName());
}
}
}