Introduction to Programming

Static initialization block

There is a similar solution for static field initialization. The static block can include the code necessary to generate values that have to be used for static field initialization: 

class SomeClass{   public String getThatString(){      return "that string";   }}public class ManageCollections {  private static Set<String> set = new HashSet<>();   static {        SomeClass someClass = new SomeClass();        set.add(someClass.getThatString());        set.add("another string");  }  public static void main(String... args){    System.out.println(set); //prints: [that string, another string]  }}

Since set is a static field, it cannot be initialized in a constructor because a constructor is called only when an instance is created, while a static field can ...