Understnading Javascript Prototype & Objects

PioStudios · 08-10-2012, 09:19 PM

Hi, I am teaching myself Javascript and I'm currently learning about Prototypes. I was wondering if anyone would be able to send me some scripts with some practical uses for prototype so that I can study it and try to understand it. Appreciate any help. Thanks, PioStudios

Old Pedant · 08-10-2012, 09:33 PM

A very simple starter:

Code:

<html>
<body>
<script type="text/javascript">
String.prototype.properCase = function() 
{
    // split the string into words after first converting it to all lower case
    // for simple example, we split on all white space characters
    var words = this.toLowerCase().split(/\s/g);

    // then loop through all the words...
    for ( var w = 0; w < words.length; ++w )
    {
        // get one word
        var word = words[w];
        // then uppercase first letter and leave other characters alone
        words[w] = word.charAt(0).toUpperCase() + word.substring(1);
    }
    // and return the joined-by-space result
    return words.join(" ");
}

document.write( "THIS is an eXAMple".properCase() );
</script>
</body>
</html>

Philip M · 08-12-2012, 10:17 AM

Code:

<script type = "text/javascript">

String.prototype.properCase = function() {
return this.toLowerCase().replace(/^(.)|\s(.)/g, 
function($1) { return $1.toUpperCase(); });
}

document.write( "THIS is an eXAMple".properCase() );

</script>

Or simpler (and better as the above and Old Pedant's scripts cannot cope with hyphens and apostrophes):-

Code:

var str1 = "jEAn-paul o'flaNAGan-macDONald"
str1 = str1.toLowerCase().replace(/\b[a-z]/g,function(w){return w.toUpperCase()});
alert(str1);

OP - have a look at
http://javascriptweblog.wordpress.co...pt-prototypes/
http://www.javascriptkit.com/javatutors/proto4.shtml

I have to say that although I understand prototypes I have rarely come across any practical situation which requires using one.

Old Pedant · 08-13-2012, 12:17 AM

Yes, I know about the sneaky way to use a regular expression in replace, but I (perhaps wrongly) assumed that would be beyond the immediate reach of somebody just learning. Reading the original post again, I can see that he said he is just learning about Prototype, not that he is just learning JavaScript.

Well, I did say it was a simple starter.