Javascript battleship game hit detection not working

Question

I'm trying to write code to detect if a ship has been hit or not. I have 3 ships on the board and each takes up 3 cells. Using js I placed the 3 ships on the board. And when I run the fire method, only the last two ships show they've been hit, but the first ship at location 00,01,02 doesn't indicate that it's been hit, even once. Where did I go wrong?

var view = {
  showMessage: function(msg) {
    var message = document.getElementById('message');
    message.innerHTML = msg;
  },

  showHit: function(location) {
    var cell = document.getElementById(location);
    cell.setAttribute('class', 'hit');
  },

  showMiss: function(location) {
    var cell = document.getElementById(location);
    cell.setAttribute('class', 'miss');
  }
}

var model = {
  boardSize: 7,
  numShips: 3,
  shipsSunk: 3,
  ships: [{
      location: [00, 01, 02],
      hits: ['', '', '']
    },
    {
      location: [10, 11, 12],
      hits: ['', '', '']
    },
    {
      location: [20, 21, 22],
      hits: ['', '', '']
    }
  ],

  fire: function(guess) {
    for (var i = 0; i < this.numShips; i++) {
      var ship = this.ships[i];
      var index = ship.location.indexOf(guess);
      if (index >= 0) {
        ship.hits[index] = 'hit';
        view.showHit(guess);
      }
    }
  }
};


model.fire(10);
model.fire(11);
model.fire(12);
model.fire(20);
model.fire(21);
model.fire(22);
/*
model.fire(00);
model.fire(01);
model.fire(02); */

* {
  margin: 0px;
  padding: 0px;
}

body {
  background-color: grey;
}

#message {
  color: green;
  font-size: 2em;
  text-transform: uppercase;
  font-family: sans-serif;
}

#board {
  background: url('board.jpg') no-repeat;
  width: 863px;
  height: 1024px;
  margin: auto;
  position: relative;
}

table {
  position: absolute;
  left: 173px;
  top: 98px;
}

td {
  height: 94px;
  width: 94px;
}

form input {
  position: absolute;
  right: 0px;
  bottom: 0px;
  background-color: green;
}

.hit {
  background: url('ship.png') no-repeat center center;
}

.miss {
  background: url('miss.png') no-repeat center center;
}

<div id='board'>
  <div id='message'></div>

  <table>
    <tr>
      <td id='00'></td>
      <td id='01'></td>
      <td id='02'></td>
      <td id='03'></td>
      <td id='04'></td>
      <td id='05'></td>
      <td id='06'></td>
    </tr>
    <tr>
      <td id='10'></td>
      <td id='11'></td>
      <td id='12'></td>
      <td id='13'></td>
      <td id='14'></td>
      <td id='15'></td>
      <td id='16'></td>
    </tr>
    <tr>
      <td id='20'></td>
      <td id='21'></td>
      <td id='22'></td>
      <td id='23'></td>
      <td id='24'></td>
      <td id='25'></td>
      <td id='26'></td>
    </tr>
    <tr>
      <td id='30'></td>
      <td id='31'></td>
      <td id='32'></td>
      <td id='33'></td>
      <td id='34'></td>
      <td id='35'></td>
      <td id='36'></td>
    </tr>
    <tr>
      <td id='40'></td>
      <td id='41'></td>
      <td id='42'></td>
      <td id='43'></td>
      <td id='44'></td>
      <td id='45'></td>
      <td id='46'></td>
    </tr>
    <tr>
      <td id='50'></td>
      <td id='51'></td>
      <td id='52'></td>
      <td id='53'></td>
      <td id='54'></td>
      <td id='55'></td>
      <td id='56'></td>
    </tr>
    <tr>
      <td id='60'></td>
      <td id='61'></td>
      <td id='62'></td>
      <td id='63'></td>
      <td id='64'></td>
      <td id='65'></td>
      <td id='66'></td>
    </tr>
  </table>
  <form action='#' method='get'>
    <input type='text' id='guessInput' placeholder='enter location: A0' />
    <input type='button' name='submit' value='Fire!' name='fire' />
  </form>
</div>

Answer 1

Your coordinates 00, 01, and 02 are interpreted as ints and are therefore resolved to 0, 1, and 2, because it is assumed that the leading zero is not needed for an int value. You can fix this by using strings to represent and compare the coordinates. Instead of model.fire(00), you will need model.fire("00"). Then to compare the input coordinates, you will need to compare guess.charAt(0) and guess.charAt(1) to determine if that coordinate is a hit.