Basic JS implementation of a little battleship

battleship.js

$(document).ready(function(){

  /* Stores the board info
    0 for empty
    1 for ship
    X when hit
  */
  var board = [];

  // Stores the locations of the ships
  var ships = [];

  // Current number of ships
  var shipNum = 2;

  // Size of the board
  var boardSize = 10;

  // Bool indicating whether or not game is over
  var gameOver = false;

  // Number of ship hits
  var hits = 0;

  // Number of guesses
  var guesses = 0;

  initializeGame();

  function initializeGame(){
    generateRandomBoard();
    printBoard();
  }

  function generateRandomBoard(){
    // Add some random ships
    var shipsAdded = 0;
    while (shipsAdded < shipNum) {
      var randomVal = Math.floor(Math.random() * (boardSize - 1));
      if (ships.indexOf(randomVal) < 0) { // Not already one of the ships
        ships.push(randomVal);
        shipsAdded++;
      }
    }

    // Set the board values based on ships added
    for(var j = 0; j < boardSize; j++) {
      if (ships.indexOf(j) < 0) { // This location not a ship
        board[j] = 0;   // Empty
      } else {
        board[j] = 1;   // Ship!
      }
    }
  }

  function printBoard() {
    var boardOut = "";
    for(var i = 0; i < boardSize; i++) {
      boardOut += board[i];
    }
    $("#board").text(boardOut);
  }

  function endGame() {
    // TODO: End game
    // ADDED FUN: Disable submit button
    console.log("End game");
    $("#end-game").text("GAME OVER!");
  }

  // CLICK HANDLERS
  $("#submit").click(userGuess);

  function userGuess(){
    var guess = $("#guess").val();
    $("#guess").val("");

    if (guess < 0 || guess > 9) {
        alert("Please enter a valid cell number!");
    } else if (guess === null){
      console.log("QUIT");
    } else {
      if (!gameOver) {
        guesses++;
        guess = parseInt(guess);
        // Check the users guess against the board for hit/miss
        if (ships.indexOf(guess) !== -1){ // HIT
          board[guess] = "X";
          hits ++;
          showResult("HIT");
        } else { // MISS
          board[guess] = "-";
          showResult("MISS");
        }

        printBoard();
        if (hits === shipNum){
          endGame();
        } else {
          // userGuess();
        }
      } else {
        endGame();
      }
    }
  }

  function showResult(result) {
    var guessDiv = $('#guess-result');
    guessDiv.text(result);
    guessDiv.show();

    window.setTimeout(function () {
      $('#guess-result').hide();
    }, 2000); // hide after 5s

    var guessCount = $("#guess-count");
    guessCount.text("Num guesses: " + guesses);
  }
});