Animal.js

class Animal {
    constructor(type, name) {
        this.type = type;
        this.name = name;
        this.votes = 0;
    }

    // Method using arrow function syntax
    toString = () => this.name + " (" + this.type + ")";
}

// This class doesn't do much, probably isn't worth making, but it's an example of extending
class Cat extends Animal {
    constructor(name) {
        super("cat", name);
    }
}

let animals = [
    {
        type: "cat",
        name: "Floof",
        votes: 0,
    },
    {
        type: "dog",
        name: "Spot",
        votes: 0
    },
    {
        type: "cat",
        name: "Max",
        votes: 0
    },
    {
        type: "elephant",
        name: "Elle",
        votes: 0
    }
]

// We could also create our animals using a class:
animals = [
    new Animal("cat", "Floof"),
    new Animal("dog", "Spot"),
    new Cat("Max"), // We could even use our Cat class that extends Animal
    new Animal("elephant", "Elle")
]

function start() {
    // const cats = animals.filter(animal => animal.type === "cat")
    // const catString = cats.join(", ")
    // alert(catString)
    alert(animals.filter(animal => animal.type === "cat").join(", "))
}

QuestionPrompt.js

class QuestionPrompt {
    constructor(question, acceptedAnswers) {
        this.question = question;
        this.acceptedAnswers = acceptedAnswers;
    }

    // Handle upper and lower case, find the accepted answer that matches
    getAcceptedAnswer = (answer) => {
        return this.acceptedAnswers.find(accepted => accepted.toLowerCase() === answer.toLowerCase())
    }

    prompt() {
        let answer = prompt(this.question);
        // Keep asking for an answer until they give one that matches the accepted answers
        while (this.getAcceptedAnswer(answer) === undefined) {
            answer = prompt(this.question + "\n\nAcceptable Answers: " + this.acceptedAnswers.join(", "));
        } 
        return this.getAcceptedAnswer(answer);
    }
}

let animals = [
    {
        type: "cat",
        name: "Floof",
        votes: 0,
    },
    {
        type: "dog",
        name: "Spot",
        votes: 0
    },
    {
        type: "cat",
        name: "Max",
        votes: 0
    },
    {
        type: "elephant",
        name: "Elle",
        votes: 0
    }
]
const animalNames = animals.map(animal => animal.name); // ["Floof", "Spot", "Max", ...]

// We can make a prompt for picking an animal to view
const ViewAnimalPrompt = new QuestionPrompt("What animal do you want to view?", animalNames);

function start() {
    let animalName = ViewAnimalPrompt.prompt();
    const animal = animals.find(a => a.name === animalName);
    alert(animal.name + " - " + animal.type);

    // We could use it multiple times, if we wanted to
    animalName = ViewAnimalPrompt.prompt();
    animal = animals.find(a => a.name === animalName);
    alert(animal.name + " - " + animal.type);

    // We could also make a prompt for the difficulty of a game
    const DifficultyPrompt = new QuestionPrompt("What difficulty?", ["Hard", "Intermediate", "Easy"]);
    let difficulty = DifficultyPrompt.prompt();
    alert("Your difficult is " + difficulty);
}

YesNoPrompt.js

class YesNoPrompt extends QuestionPrompt {
    constructor(question) {
        // Call the constructor on QuestionPrompt with these two parameters
        super(question, ["Yes", "No", "Y", "N"]);
    }

    prompt() {
        // Call the prompt function on QuestionPrompt and get the value returned from it
        let answer = super.prompt() 
        // Convert it into a boolean and return that
        let booleanAnswer = (answer === "Yes" || answer === "Y");
        return booleanAnswer;
    }
}

const ShouldContinuePrompt = new YesNoPrompt("Should we continue?");

// You could use this to confirm if they want to delete
const ShouldIDeletePrompt = new YesNoPrompt("Should I delete?")

function start() {
    const shouldContinue = ShouldContinuePrompt.prompt();
    // alert(shouldContinue);
    if(shouldContinue) {
        // Continue with something
    }
    // You could use it again if you need to ask the question again
    const shouldContinueAgain = ShouldContinuePrompt.prompt();
}