Java Tutorials

Initialization Blocks

• A class can have initialization blocks to set up fields or other necessary states.
• Typically these blocks are static.
• Most useful when simple initialization clauses on a field declaration need a little help.

      class Primes {
         protected static int[] knownPrimes = new int[4];
         static
         {
            knownPrimes[0] = 2;
            for (int i=1; i<knownPrimes.length; i++)
            {
               knownPrimes[i] = nextPrime();
            }
         }
      }
  

• You can also have non-static initialization blocks.