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This video is going to cover the solution for part four, looking back at the requirements be classified,

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another type of object, the contact manager and the contact manager as identified by the contacts that

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it manages.

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And it has two actions, adding and removing contacts.

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We'll start by adding the contacts.

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Field contact is plural, so it implies an array of Carra objects.

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But we're going to use an array list because the number of elements can change.

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As always of a class has failed, you need to apply the big three steps, we need to take instructor

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at Getter and Setter.

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The instructor is public shares the same name as the class, and it's going to receive no parameters

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because in the beginning, the list of contacts is going to be empty.

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We're just going to set the field equal to a new area list that can store contact objects.

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Next, we want to get her gut contact that receives a one parameter.

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The index of the contact object that they're trying to access.

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In this letter is going to return a new copy of the contact object.

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At the request, that index.

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Next, we want to add a Seder that receives two parameters.

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Contact object that you're going to use to update one of your Helmut's.

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The index of the element that you want to update.

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Then we're going to set the element at the requested index.

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And set it equal to a new copy of the object being Pastan.

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OK, that's all for the Big Three Steps.

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Now we're going to get the method and contact, it's going to be void.

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Receives one parameter, the contact they are trying to add.

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And inside, we're going to insert a new copy of the contact object being Pastan.

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The next action removes contact is also going to be void.

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But it receives one parameter, the name of the contact that you want to remove.

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So what we'll do is create a for loop that runs through the size of the array list.

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Remember that array, less of a size, not a length and inside the loop.

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We're going to get the contact object that every index I.

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We'll get the name field of the contact and we'll check if it equals the name that was passed PASTAN

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and if that's the case, then we're going to remove that contact from the aerialists.

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Perfect.

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We're done adding the big three steps, we added the two actions, the last thing we got to do is add

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a two string method.

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As always, public string to string.

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I'm going to create a string named temp for a temporary it's going to be an empty string for now and

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we'll return it's.

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First will create a for loop that runs through the size of the aerialists.

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And during each run, I'm going to get the two string of the contact object at the index I.

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And then when I add that strength to the temp variable that we're returning.

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And after adding the two string of a contact, we can add two lines so that we can separate it from

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the next two string that gets passed into it.

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And that's it now we're going to test our code.

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Inside the workbook, I left you some values for objects that I want you to create.

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First all, create an object of the contact manager class.

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Manager is equal to a new object of the contact manager class.

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And for the sake of expediency, I'm going to call that contact three times.

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Once for Ryan.

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Joe.

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And Thomas.

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Finally, we can print the contact to manager.

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By printing the contract to manage our Java internally calls the two string method, which is going

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to return a nicely formatted string of every contact and the contact lists.

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Beautiful.

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So the adduction works.

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Now we're going to test the remove action, I'm going to remove the contact name Geo.

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We run the up.

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And everything works well.

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This is the solution for part four.