A class consists of constructors that are used to generate objects from the class blueprint. Constructor declarations are similar to method declarations, with the exception that they do not have a return type and utilize the class name. For instance, Bicycle has a single constructor:

public Bicycle(int startCadence, int startSpeed, int startGear) {
	gear = startGear;
	cadence = startCadence;
	speed = startSpeed;
}

A constructor is invoked by the new operator to generate a new Bicycle object named myBike:
Bicycle myBike = new Bicycle(30, 0, 8);
new Bicycle(30, 0, 8) creates space in memory for the object and initializes its fields.
Despite the fact that Bicycle has only one constructor, it is possible that it could have additional constructors, such as a no-argument constructor:

public Bicycle() {
	gear = 1;
	cadence = 10;
	speed = 0;
}

Bicycle yourBike = new Bicycle();
The Bicycle class uses a constructor called the no-argument constructor to generate a new object named yourBike. The Java platform differentiates constructors based on the number of parameters in the list and their types, making it impossible to create two constructors for the same class with the same number and type of parameters. It is not required to include constructors in a class, but caution is advised. If a class lacks constructors, the compiler generates a default constructor that invokes the no-argument constructor of the superclass. It is possible to employ a superclass constructor independently, as demonstrated in the MountainBike class. Access modifiers can be implemented in the constructor declaration to regulate the ability of other classes to invoke it.

*Note: A MyClass object cannot be directly created by another class if it is unable to invoke the MyClass constructor.