Using Initialization Blocks: A non-static initialization block : Initialization Block « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Initialization Block

1. Executed for each object that is created.
2. Can initialize instance variables in a class.

public class MainClass {
  static int[] values = new int[10];

  {
    System.out.println("Running initialization block.");
    for (int i = 0; i < values.length; i++) {
      values[i] = (int) (100.0 * Math.random());
    }
  }

  void listValues() {

    for (int value : values) {
      System.out.println(value);
    }

  }

  public static void main(String[] args) {
    MainClass example = new MainClass();
    System.out.println("\nFirst object:");
    example.listValues();

    example = new MainClass();
    System.out.println("\nSecond object:");
    example.listValues();
  }
}

Running initialization block.

First object:
35
17
1
10
42
38
42
71
24
7
Running initialization block.

Second object:
45
78
49
9
11
36
0
18
56
38