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When you add in equals method, you must always add the hash code method.

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In this lesson, you will add an equals method, any hash code method to the children classes.

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We're not going to add an equals method or a hash code method to the parent class, it's impossible

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to create an object of the product.

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There's nothing that can be equal to Serenity's the Java code generators that an equals and hash code

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method to the short class.

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Auto import, the objects, utility costs.

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And this equals isn't complete, it has to compare every field from both objects, but it's only comparing

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the size field and I find this a bit awkward.

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I'd rather just say this size equals shirt that size.

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OK, how do we compare the inherited fields, remember, that super refers to the super class, which

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also means the parent class.

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Superdog, a method calls a method from the parent class.

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So we'll check if Superdog get price.

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Equal share target price.

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Superdog, get color.

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Equal shirt, get color.

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And Superjet brand.

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Equal shirt, douget brand.

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Before we continue, super refers to the parent class superdog, get price calls, the get price method

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from inside the parent class and get price is going to return the price value of the current object

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that's calling this method.

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OK, now here, make sure this has a hash, not hash code, if the generator only sees one field that

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defaults, the calling the objects that hash code method, but we need to call it hash because it accepts

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many arguments.

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And here we have to add the remaining fields using the getas superdog set price superdog, that color.

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And Superdog get brand.

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The passcode good method needs to always stay consistent with your equals method.

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All right, now I can check if shirt and shirt to our equal.

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So run the debugger.

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This points to the current object that's calling this method of points to the object that was passed

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into the equals method, the two objects don't share the same reference.

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So this is suspect.

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The object being passed in is an instance of the Sherpas.

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So it passes this test and you can typecast it and now we can compare the size.

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And here super refers to the parent class superdog, get price calls, the get priced method from inside

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the parent class.

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And get price is going to return the price value of the current object.

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The price of that object is the same as the one we're comparing it to, the color is the same, the

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brand is the same.

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So ultimately equals returns.

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True, these objects are equal.

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All right, and now I'm going to print the hash good of both objects.

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Endure the same Perfect's passcode method must always assign equal objects, the same hash code, this

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rule is so important and if you don't follow it, you're going to get bugs on that very same topic.

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I want to remind you once again, because this is so important, when you override an equals method,

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you must always, always override the hash code method.

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If you don't do that, you're breaking the equality contract and you're going to get so many bugs.

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Anyway, so we're good.

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I want to talk about one more thing before we wrap up this versus super.

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This can call local methods and inherited methods.

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Super can only call inherited methods.

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So going back to our code, let me ask you this, should we use this or super.

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Super, we don't want the added flexibility because it's dangerous.

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This is perfectly capable of calling an inherited method.

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In fact, rerun the debugger.

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This points to the current object that's calling the equals method.

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The current object inherits a get price method, so it's capable of calling it price get price returns,

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the price of the current object.

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OK.

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But now what if in the future I end up creating a random method that happens to be called get price

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inside the shirtless?

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And we'll just return three.

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Now restart the runtime.

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This is going to prioritize the local method.

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Even though we wanted to call the inherited method, and that's why we don't want to use this, it's

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more flexible, which also makes it more dangerous.

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And in my opinion, a good code should protect you from yourself.

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So if you put super, the current object is going to call the inherited method no matter what.

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So restart the runtime.

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Super refers to the super class, the parent class, so super doget price is going to call the get price

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method inside the parent class no matter what.

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Now, that being said, I always use super to call an inherited method.

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But this year can still cause problems, so just make sure to remove it.

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All right, now we'll do the same thing inside the pants class, use the Java code generator stat equals

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method, any hash code method.

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We need to compared the other three fields, so we'll check if superguy price.

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Equals penstock get price.

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If superdog that color.

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Equals pants that get color.

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And if Superjet brand.

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Equals Penstock get brand.

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OK, now here, make sure this has hash, not hash code, because hash can accept many arguments and

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we need to pass in three of them.

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Superdog get price, superdog at color.

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And supermarket brand.

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I'm not going to test this code, you can feel free to do so on your own time, it should behave the

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same as what we did for the short class.

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Let's recap, you created the equals and hash code method inside the children classes.

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And Superdog Method calls a method inside the parent class.