game.js

var buttonColors = ["red", "blue", "green", "yellow"];
var gamePattern = [];
var userClickedPattern = [];
var started = false;
var level = 0;

// Detect keypress
$(document).on("keydown", function() {
    if (!started) {
        $("#level-title").text("Level " + level);
        nextSequence();
        started = true;
    }
});

// Detect user click for 'this' button and save pattern in user pattern
$(".btn").on("click", function() {
    var userChosenColor = $(this).attr("id");
    userClickedPattern.push(userChosenColor);
    playSound(userChosenColor);
    animatePress(userChosenColor);
    checkAnswer(userClickedPattern.length - 1)

});

function checkAnswer(currentLevel) {
    if (userClickedPattern[currentLevel] === gamePattern[currentLevel]) {
        console.log("success");
        if (userClickedPattern.length === gamePattern.length) {
            setTimeout(function() {
                nextSequence();
            }, 1000);
        }

    } else {
        console.log("wrong");
        playSound("wrong");
        $("body").addClass("game-over");
        setTimeout(function() {
            $("body").removeClass("game-over");
        }, 200)
        $("#level-title").text("Game over, press any key to restart.")
        startOver();
    }
};

function nextSequence() {
    userClickedPattern = [];
    level++;
    $("#level-title").text("Level " + level);
    // Choose random color and add to game pattern
    var randomNumber = Math.floor(Math.random() * 4);
    var randomChosenColor = buttonColors[randomNumber];
    gamePattern.push(randomChosenColor);
    // Use jQuery to select the button with the same id as the randomChosenColor
    $("#" + randomChosenColor).fadeIn(100).fadeOut(100).fadeIn(100);
    // Play sound for chosen color
    playSound(randomChosenColor);
    animatePress(randomChosenColor);
};

function playSound(name) {
    var audio = new Audio("sounds/" + name + ".mp3");
    audio.play();
};

function animatePress(currentColor) {
    $("#" + currentColor).addClass("pressed");
    setTimeout(function() {
        $("#" + currentColor).removeClass("pressed");
    }, 100);
};

function startOver() {
    level = 0;
    gamePattern = [];
    started = false;
}