Mar 22, 2020
Prinicple of Industrial Instrumentation Third Edition D Patranabis Pdf 166. ABIMAN T.O. AND ALEXANDER S. .
Category:Analytical chemistry
Category:Instrumentation
Category:Chemical engineering
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Category:Instrumentation
Category:Hazardous materialsQ:
Working with (or avoiding) the use of 'this' keyword
Here is a situation I am having trouble figuring out a good and effective way to handle.
I have an ArrayList of Car objects. The Car objects are created in a constructor:
public ArrayList cars = new ArrayList ();
The ArrayList is passed into the constructor of my CarList:
public CarList(ArrayList cars) {
super(cars);
}
And then there are methods which get invoked by my logic in the CarList.
I want to be able to alter the elements of the ArrayList while maintaining the state of the CarList class.
Right now, I am doing something like this:
public void updateCar(Car c) {
this.cars.add(c);
}
I am pretty sure this is wrong. Is there a better way? Can I avoid using the 'this' keyword? What is a better alternative?
Note: I know I can just make the ArrayList a member variable of the CarList class. I am not trying to do that right now. I just want to figure out how to make the ArrayList accessible to the outside world.
A:
You can get rid of the parameter to the constructor of CarList, then CarList will have a collection of Car objects that it can mutate.
// somewhere, as a class field:
private ArrayList cars;
public CarList() {
super();
cars = new ArrayList();
}
public void updateCar(Car c) {
cars.add(c);
}
(or you can make the ArrayList a member of CarList, and pass a reference to it instead of a collection)
Note: I would also make the superclass's constructor take an argument of the type of the collection.
A:
Just pass the ArrayList ac619d1d87
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