Java Basics Using Qt Jambi Tutorial

Constructors

Constructors are used to initialize our variables but this is optional. As I've said, there is already a default constructor created for us.

Ex.

public class Vehicle{

public Vehicle(int wheels){

this.wheels = wheels;

}

}

There are rules in creating constructors:

1. It should have the same name as your class.

2. It does not have a return type.

3. You can create as many constructors provided you must have different number of parameters or different type.

Ex.

public class Vehicle{

public Vehicle(int wheels){

}

public Vehicle(String color, int doors){

}

public Vehicle(int gears, int steeringwheels){

}

}

Note: It is recommended you use different name for your parameters from the class variables.

Ex.

public class Vehicle{

public int trunk;

public String type;

public Vehicle(int wheels, int gears){

trunk = 1;

type = “car”;

wheels = 4;

gears = 6;

}

}

If you have same variable names for your parameters and class variables use the keyword “this.”

Ex.

public class Vehicle{

public int wheels;

public int gears;

public Vehicle(int wheels, int gears){

this.wheels = wheels;

this.gears = gears;

}

}

to be continued...