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Object-Oriented JavaScript: Challenge

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Player Properties Solution

2:57 with Ashley Boucher

See the solution for the what properties will be used in the Player Class.

Default Values


Note: This explanation will also be repeated later in the course.

Default values are a way to initialize parameters with a specific value, even if no value or undefined is passed.

If an argument is passed for that parameter, the parameter will be initialized with the passed value.

If an argument is not passed, the parameter will be initialized with the default value.

In the following example, the company parameter has a default value of "Treehouse". If no third argument is sent when the function is called, the parameter company will still be available in the function, with a value of "Treehouse".

const name = 'Ashley';
const job = 'teacher';

printEmployee(name, job);

printEmployee(name, job, company = 'Treehouse') {
    //function code here
}

MDN Docs - Default Values

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    Hey, there. 0:00
    Welcome back. 0:00
    What did you come up with? 0:01
    Hopefully you found the brainstorming exercise useful. 0:03
    As we go through the Player properties we'll be using for this app, 0:05
    it takes some time to compare and contrast our solutions. 0:09
    And keep in mind, when I built this project, I rewrote my classes and 0:12
    constructor methods several times. 0:15
    You're seeing the final outcome of a long process here. 0:17
    Please remember that there were a ton of iterations 0:21
    before this that you're not seeing. 0:23
    Okay, I've got my Player class decoration here, in a file called Player.js. 0:25
    Does your syntax for the class decoration match what you see on screen? 0:31
    If not, pause the video here and adjust your code. 0:35
    Inside our Player class, we'll add an empty constructor method together and 0:38
    then chat about the properties that we'll be using. 0:42
    If you recall from previous course work on OOJS, 0:45
    constructor methods go inside the class declaration. 0:48
    These are the factory for your class. 0:51
    Where properties are assigned to a new object of that class type. 0:53
    To write one, don't forget that you use the lower case keyword, constructor. 0:58
    Now, as for our properties, the first property will be name. 1:05
    Players should also have a unique id. 1:12
    An id property could probably be used a few ways, but 1:14
    we'll be using it to help identify which player the tokens belong to. 1:17
    You'll see that in upcoming steps. 1:22
    The players will also have a color property. 1:24
    This way when we render the tokens in HTML, 1:27
    we will be able to tell the players tokens apart. 1:30
    The values for each of these properties will be passed in as arguments when we 1:33
    instantiate the two player objects. 1:37
    We'll get to that later, but for now, let's be sure to add those parameters Now, 1:39
    there should also be a way to track of whether or not it's a given player's turn. 1:47
    Add a property called active, which will hold the boolean value. 1:51
    In our argument list, we'll give active a default value of false. 1:55
    This way, when the Player object is instantiated, 1:59
    it can be assumed that it's not their turn unless otherwise explicitly stated. 2:02
    The final property, tokens, will hold an array of that player's tokens. 2:07
    We'll create a method to generate these tokens in a future step. 2:11
    So for now, we'll set the tokens property to an empty array. 2:15
    We won't be passing an argument in for this property. 2:18
    Okay, so to review, we've added the following properties to our Player class. 2:21
    name, id, color, active and tokens. 2:26
    Most of the values for 2:31
    this properties will be passed in when the player objects are created. 2:32
    The exception to this is the tokens property. 2:36
    In a future step, we'll be writing a method inside this class that 2:39
    creates the token objects for us. 2:43
    So for now, we've just set this property to an empty array. 2:45
    Now that we've finished the Player constructor method and 2:49
    added all of the properties, let's move on and start brainstorming the properties for 2:51
    the token object. 2:56

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