Nullary constructor

A nullary constructor is a constructor that takes no arguments.

Java

Example

public class Example 
{
  // nullary constructor
  public Example()
  {
     this.data = 1;
  }
  
  // non-nullary constructor 
  public Example(int data)
  {
     this.data = data;
  }
  
  protected int data;
}

Haskell

Example

-- nullary type constructor with two nullary data constructors
data Bool = False | True

-- non-nullary type constructor with non-nullary data constructor
data Point a = Point a a