Scala has two kinds of constructors:

• Primary Constructor
• Auxiliary Constructor

Primary Constructor: In Scala, Primary Constructor is a constructor which is defined with class definition itself. Each class must have one Primary Constructor: Either PARAMETER constructor or Parameterless constructor.

Example:-

class Person

Above Person class has one Zero-parameter or No-Parameter or Parameterless Primary constructor to create instances of this class.

class Person (firstName: STRING, lastName: String)

Above Person class has a two PARAMETERS Primary constructor to create instances of this class.

Auxiliary Constructor: Auxiliary Constructor is also known as Secondary Constructor. We can declare a Secondary Constructor USING ‘def’ and ‘this’ keywords as shown below:

class Person (firstName: String, middleName:String, lastName: String){
def this(firstName: String, lastName: String){
this(firstName, "", lastName)
}
}

Scala has two kinds of constructors:

Primary Constructor: In Scala, Primary Constructor is a constructor which is defined with class definition itself. Each class must have one Primary Constructor: Either Parameter constructor or Parameterless constructor.

Example:-

class Person

Above Person class has one Zero-parameter or No-Parameter or Parameterless Primary constructor to create instances of this class.

class Person (firstName: String, lastName: String)

Above Person class has a two Parameters Primary constructor to create instances of this class.

Auxiliary Constructor: Auxiliary Constructor is also known as Secondary Constructor. We can declare a Secondary Constructor using ‘def’ and ‘this’ keywords as shown below:

class Person (firstName: String, middleName:String, lastName: String){
def this(firstName: String, lastName: String){
this(firstName, "", lastName)
}
}