Integer Types

1. byte (1 byte)
      e.g.  byte whatever;           // default initial value (0)
      e.g.  byte whatever = 10;   // initial value
2. short (2 bytes)
3. int (4 bytes)
4. long (8 bytes)

Floating Point Types

1. float (4 bytes)
   e.g.   float money;  
   e.g.   float money = 100.00;
2. double (8 bytes)

Character Types

1. char (2 bytes, Unicode)
      e.g. char initial;
      e.g. char initial = 'a';
   
   Unicode characters can also be specified using '\u0000' through '\uFFFF'.  '\u0000' through '\u00FF' correspond to ordinary ASCII/ANSI characters.  If you would like to find out more about Unicode, visit www.unicode.org.
   
2. String (an array of characters, strictly speaking this is not a simple data type, but since it is built-in to the language, it at least appears "simple")
      e.g. String name;                  // array still not created
      e.g. String name = "java";     // array created and initialized
      e.g. char letter = name[0];    // letter assigned the character j

Boolean Types

1. boolean (legal values: true, false)
      e.g.   boolean flag = true;    // initial value of true