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createTokens() Method Solution

3:06 with Ashley Boucher

See the solution for the createTokens() method assignment.

JS Documentation

To read more about how to document your JS code, visit http://usejsdoc.org/.

Code Documentation Correction

The project files are correct, but there's a small error in what you see on screen.

The documentation for this method is missing the @param information. The complete documentation should look like this:

/**
  * Creates token objects for player
  * @param   {integer}   num - Number of token objects to be created
  * @return  {array}     tokens - an array of new token objects
  */

Solution Code

Player class constructor method:

constructor(name, id, color, active = false) {
        this.name = name;
        this.id = id;
        this.color = color;
        this.active = active;
        this.tokens = this.createTokens(21);
}

Player class createTokens() method:

/**
 * Creates token objects for player
 * @param   {integer}   num - Number of token objects to be created
 * @return  {array}     tokens - an arary of new token objects
 */
createTokens(num) {
    const tokens = [];

    for (let i = 0; i < num; i++) {
        let token = new Token(i, this);
        tokens.push(token);
    }

    return tokens;
}
  • 0:00

    Welcome back.

  • 0:01

    How did you feel about writing this method?

  • 0:03

    Don't worry if you had any trouble, the solution for

  • 0:05

    this method is up on screen and I'm going to walk you through it now.

  • 0:09

    I'm inside my player.js file where I wrote the method.

  • 0:12

    As you can see, just below my constructor method, I created the method createTokens.

  • 0:19

    It accepts one parameter, num.

  • 0:21

    Num represents the number of token objects to be created.

  • 0:26

    Inside the method I created a variable called tokens

  • 0:30

    that's equal to an empty array.

  • 0:33

    This array will be populated in the following lines of code,

  • 0:37

    with all of our new token objects, and the array will then be returned.

  • 0:41

    After creating the empty array, I wrote a for loop that will iterate num times.

  • 0:48

    Inside the for loop, I do two things,

  • 0:51

    first I create a variable called token and set it equal to new Token object.

  • 0:56

    This is where the loop index and

  • 0:58

    the owning player object are passed to the token's constructor method.

  • 1:03

    After that, I add the newly created token to my tokens array using the push method.

  • 1:08

    When the loop is finished and all the tokens have been created,

  • 1:12

    I return the array.

  • 1:13

    But where's it being returned to?

  • 1:16

    Part of your assignment for

  • 1:18

    this step was to call the create tokens method from inside the constructor method.

  • 1:22

    By changing the tokens property to be set to the return value from the method call.

  • 1:27

    If you jump up to the constructive method, you can take a look at this.

  • 1:32

    As you can see I've set the token property to the return value from the method call.

  • 1:38

    Note how when I call the create tokens method, I'm using the this keyword.

  • 1:42

    Indicating that the method I want to call is available on the object that we're

  • 1:46

    initializing.

  • 1:47

    I've also passed the number 21 as an argument to the createTokens method.

  • 1:52

    21 might seem like an arbitrary number, but

  • 1:55

    you'll see later when we write the code that builds out the board and spaces,

  • 2:00

    that 21 is equal to half of the number of spaces on the board.

  • 2:04

    Each player gets 21 tokens total.

  • 2:06

    So that the game board can be completely filled without

  • 2:10

    having any tokens left over.

  • 2:11

    If you wanted you could make the game more difficult by reducing the number of

  • 2:16

    tokens.

  • 2:16

    This would limit the number of opportunities that a player had to

  • 2:20

    make a winning move.

  • 2:21

    Before you move on,

  • 2:22

    I would like to talk to you about the commenting you see above my method.

  • 2:26

    This is a commonly used way to document JavaScript code.

  • 2:29

    Every method in your classes should be documented like this.

  • 2:32

    This way, anyone, including yourself if it's been a while since you've worked

  • 2:36

    with a code base, can quickly figure out what each method is responsible for.

  • 2:40

    The documentation should give a quick summary of the method, and

  • 2:44

    then describe any arguments it receives, and anything that's returned.

  • 2:48

    Check out the teacher's notes for a link to a website that describes the syntax you

  • 2:53

    should use for this documentation in detail.

  • 2:55

    Okay, take a moment to make any necessary changes to your code so

  • 2:59

    that it matches the solution you see on-screen.

  • 3:02

    And then head over to the next step, where you will start building out the board.

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