We would like to know how to modify array prototype.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
<!--from ww w . j av a 2 s.co m-->
Object.defineProperty(Array.prototype, 'x', {
enumerable: false,
value: 10
});
var a = ['first', 'second', 'third'],
s = '';
for (var i in a) {
s += '<br/>a[' + i + '] = ' + a[i];
}
document.writeln( s + '<br/>a.x=' + a.x);
</script>
</head>
<body>
<p id="res"></p>
</body>
</html>
The code above is rendered as follows: