A constructor belongs to a particular class object that is instantiated. The constructor initializes this object and can provide access to its private information. The concept of a constructor can be applied to most object-oriented programming languages. Essentially, a constructor in JavaScript is usually declared at the instance of a class.


// This is a generic default constructor class Default
function Default() {}

// This is an overloaded constructor class Overloaded
// with parameter arguments
function Overloaded(arg1, arg2, /* …, */ argN) {}

To call the constructor of the class in JavaScript, use a new operator to assign a new object reference to a variable.

function Default() {}

// A new reference of a Default object assigned to a
// local variable defaultReference
const defaultReference = new Default();

See also