Get Max of Array

http://stackoverflow.com/questions/37309823/jquery-each-strange-calculation#37309886

by dixalex

HTML

<div id="zone1" data-top="38" data-bottom="1648" data-left="131" data-width="467" data-group="0">...</div>
<div id="zone2" data-top="38" data-bottom="957" data-left="597" data-width="467" data-group="0">...</div>
<div id="zone3" data-top="38" data-bottom="4508" data-left="1064" data-width="467" data-group="0">...</div>
<p>
  data-bottom max value is: <span class='maxItem'></span>
</p>

CSS

.maxItem {
  color: orange;
}

p {
  font-family: arial;
}

JavaScript

//http://stackoverflow.com/a/1669222/5076162

var botArray = [];

$('[data-group=0]').each(function() {
  var item = parseInt($(this).attr('data-bottom'), 10);
  botArray.push(item);
});

var max = Array.prototype.max = function() {
  return Math.max.apply(null, botArray);
};

$('.maxItem').text(max);