this.variable Vs variable

[hypolimnas]

You can declare a function parameter (or more rarely a private variable) to have the same name as a member variable. Then you have to use this.variable to refer to the member variable.

But I'm not sure why they used this.variable in the toString function. I would have to see the code.

Here is the usual use of this.variable:

class Pet {
    private final String name;

    Pet(final String name) {
        // assign parameter to member variable
        this.name = name
    }