viebrock.ca

The comment about obfuscating email addresses led me to look for Javascript functions that reverse a string, or translate characters á la PHP’s strtr() function.

Of course, they don’t exist natively, so here are my versions that extent the String class:

String.prototype.reverse = function() {
	var str=’‘;
	for (i=this.length-1;i>=0;i—) {
		str += this.charAt(i);
	}
	return str;
}</p>

	<p>String.prototype.translate = function(from,to) {
	var sl = this.length;
	var tl = to.length;
	var xlat = new Array();
	var str = ‘’;</p>

	<p>	if (sl<1 || tl<1) return this;</p>

	<p>	for (i=0; i<256; xlat[i]=i, i++);</p>

	<p>	for (i=0; i<tl; i++) {
		xlat[ from.charCodeAt(i) ] = to.charCodeAt(i);
	}</p>

	<p>	for (i=0; i<sl; i++) {
		str += String.fromCharCode( xlat[ this.charCodeAt(i) ] );
	}
	return str;
}</p>

	<p>var msg = “Hello world!”;</p>

	<p>alert(msg.reverse());</p>

	<p>alert(msg.translate(‘lor’,‘gis’));

The code for the translate() method was copied from the PHP source code. If there are more efficient ways to do it, feel free to comment!