Iterating over Enum Values in Java

Enum in Java is a data type that contains a fixed set of constants. A Java enum type is a special kind of Java class. An enum can contain constants, methods, etc.

Given below is a demonstration of how to declare an enum:  

Iterate over Enum Values: There are many ways to iterate over enum values:  

1. Iterate Using forEach()
2. Iterate Using for Loop
3. Iterate Using java.util.stream 

Iterate Using forEach(): The forEach() method works on list or set. For using forEach() method, convert enum into list or set. 

Conversion of enum to set and applying forEach has been shown below: 

EnumSet.allOf(seasons.class)
            .forEach(season -> System.out.println(season));

Conversion of enum to list and applying forEach has been shown below: 

Arrays.asList(seasons.values()).
                forEach(season -> System.out.println(season));

The below program illustrate the iteration over enums using forEach(): 

Spring
Summer
Monsoon
Autumn
Winter
Spring
Summer
Monsoon
Autumn
Winter

Iterate Using for Loop: The static values() method of java.lang. Enum class gives an array of enum values. After getting an array of enum values iteration over the array can be done using for loop.

Below program illustrate the iteration over enum using for loop: 

Spring
Summer
Monsoon
Autumn
Winter

Iterate Using java.util.stream: Iteration over enum can also be done using java.util.stream class. Create the stream of enum.values() using Stream.of() method by passing eum.values() at parameter to function. 

The below program illustrates the iteration over enum using java. util.stream: 

Spring
Summer
Monsoon
Autumn
Winter

Reference: https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html