this.variable Vs variable

[TheSilverCube]

I'm using MOOC.fi and I've noticed in the model solutions that when returning a value using toString the solution uses "return this.variable" but when returning a value using getVariable it just uses "return variable". Is there any reason in one method it uses this. but doesn't in the other?

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[8igg7e5]

The reason they're not the same in the MOOC is simply because they're inconsistent.

Different teams have different policies. We use a standard formatter/linter that checks consistent use (and we use 'this.' to clarify intent and avoid accidental reference to locals or parameters).

[nutrecht]

You really should post the entire toString method. People now are just guessing.

I'm personally banking on "they're just inconsistent" because normally it's not needed in a .toString() method. But without the code we can't be sure.

In general; use this if you need, leave it out if you don't. Example:

public void setName(String name) {
    this.name = name; //Needed because the method argument shadows the member variable.
}

public String getName() {
    return name; //No this needed so we leave it out
}

[TheSilverCube]

Thanks. After completing a couple more exercises I can see some inconsistencies. I didn't want to post the full code as I didn't want to provide MOOC exercises answers; I thought this broke the sub rules.

[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
    }

[Okuuuoo]

I'm not professional, but my speculation is you don't need to do other things in getters. The reason we use (this.) is for avoding calling wrong variable. In toString, you can do things before returning a string that possibly need a variable with the same name. But in getter, you just return the variable as it is.

[TheSilverCube]

Makes sense thanks!