this Keyword Practice Test

In the code snippet below, what problem does 'this' solve in the provided class definition?

class Rectangle {

    private int length;

    private int width;

    public Rectangle(int length, int width) {

        // 'this' distinguishes instance variables from parameters

        this.length = length;

        this.width = width;

    }

    public int area() {

        // method call on the current object

        return this.computeArea();

    }

    private int computeArea() {

        return length * width;

    }

}

Refer to the Car class code below. How does the 'this' keyword affect the method invocation inside getDetails()?

class Car {

    private String brand;

    private String model;

    public Car(String brand, String model) {

        // 'this' distinguishes fields from same-named parameters

        this.brand = brand;

        this.model = model;

    }

    public String getDetails() {

        // 'this' invokes an instance method on the current object

        return this.formatDetails();

    }

    private String formatDetails() {

        return brand + " " + model;

    }

}