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Initialization of a class consists of executing its static initializers and the initializers for static fields (class variables) declared in the class.

ThisIn statementother assertswords, that the presence of a {{static}} field triggers the initialization of a class. However, a static field might depend on the initialization of a class, and might create an initialization cycle. The Java Language Specification also states: (\[[JLS 2005|AA. Bibliography#JLS 05]\], Section 8.3.2.1, "Initializers for Class Variables")

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Noncompliant Code Example (intra-class cycle)

Wiki MarkupIn this noncompliant code example, a recursive attempt is being made to initialize the class, creating an initialization cycle. Because such recursive attempts are ignored by the JVM, the default value of {{deposit}} is {{0}} during the initialization \[[Bloch 2005|AA. Bibliography#Bloch 05]\]. The code tries to calculate the account balance by subtracting the processing fee from the deposited amount, but fails to do so. The {{Cycle}} class object {{c}} is instantiated before the {{deposit}} field gets initialized.

public class Cycle {
  private static final Cycle c = new Cycle();
  private final int balance;
  private static final int deposit = (int) (Math.random() * 100); // Random deposit

  public Cycle() {
    balance = deposit - 10; // Subtract processing fee
  }

  public static void main(String[] args) {
    System.out.println("The account balance is: " + c.balance);	
  }
}

Because such recursive attempts are ignored by the JVM, the default value of {{deposit}} is {{0}} during the initialization \[[Bloch 2005|AA. Bibliography#Bloch 05]\].  The code tries to calculate the account balance by subtracting the processing fee from the deposited amount, but fails to do so. The {{Cycle}} class object {{c}} is instantiated before the {{deposit}} field is initialized. As a result, the constructor {{Cycle()}} is invoked which computes the balance based on the initial value of {{deposit}} (0) rather than the random value. As a result, the balance

 is always equal to {{-10}}.  

Compliant Solution (intra-class cycle)

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