string2charCodeString encodes the entire string to charCode values. idEncode converts a string into a valid HTML id attribute [A-Za-z0-9_-]. Useful for producing readable window.location.hash fragments

charCode-encode-string.js

	// Example:
	// http://github.com/chris/project123/blob/master/new_mailer/install-file.rb
	// 104-116-116-112-58-47-47-103-105-116-104-117-98-46-99-111-109-47-99-104-114-105-115-47-112-114-111-106-101-99-116-49-50-51-47-98-108-111-98-47-109-97-115-116-101-114-47-110-101-119-95-109-97-105-108-101-114-47-105-110-115-116-97-108-108-45-102-105-108-101-46-114-98
	function string2charCodeString (s){
		if(typeof(s) != 'string') return false;
		a = [];
		f = s.length;
		for (i = 0; i<f; i++) {
			a[i] = s.charCodeAt(i);
		}
		return a.join('-');
	}
	
	function charCodeString2string (s){
		if(typeof(s) != 'string') return false;
		s2 = '';
		a = s.split('-');
		f = a.length;
		for (i = 0; i<f; i++) {
			s2 += String.fromCharCode(parseInt(a[i]));
		}
		return s2;
	}
	
	var string1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
	var string2 = "`-=~!@#$%^&*()_+{}[];:'\"?/><,.\\|";
	var string3 = "http://github.com/chris/project123/blob/master/new_mailer/install-file.rb";
	var string4 = '';
	
	var encode1 = string2charCodeString(string1);
	var encode2 = string2charCodeString(string2);
	var encode3 = string2charCodeString(string3);		
	var encode4 = string2charCodeString(string4);	
	
	var decode1 = charCodeString2string(encode1);
	var decode2 = charCodeString2string(encode2);
	var decode3 = charCodeString2string(encode3);
	var decode4 = charCodeString2string(encode4);
	
	console.log(string1);
	console.log(encode1);
	console.log(decode1);
	
	console.log(string2);
	console.log(encode2);
	console.log(decode2);
	
	console.log(string3);
	console.log(encode3);
	console.log(decode3);
	
	console.log(string4);
	console.log(encode4);
	console.log(decode4);

id-charCode-encode-string.js

	// idEncode converts a string into a valid HTML id attribute [A-Za-z0-9_-] 
	// Useful for producing readable window.location.hash fragments
	//
	// Params:
	// "s" string to encode
	// "prefix" to be affixed before the encoded string - HTML id attributes must start with an [A-Za-z] char
	// "exclude" regex string of characters that should not be encoded
	// "spacer" the character that joins encoded items
	// "replace" object of post-encoded strings to str.replace e.g. {"-47-" = "_"} replaces all encoded "/" chars with a "_" 
	//
	// Example:
	// http://github.com/chris/project123/blob/master/new_mailer/install-file.rb
	// id_http-58-__github-46-com_chris_project123_blob_master_new-95-mailer_install-45-file-46-rb
	
	function idEncode ( s, prefix, exclude, spacer, replace )
	{
		if(typeof(s) != 'string') return false;
		
		prefix = typeof(prefix) != 'undefined' ? prefix : 'id_'; // use '' to not add any prefix
		exclude = typeof(exclude) != 'undefined' ? exclude : '[^A-Za-z0-9]'; // use '.' to encode every character
		spacer = typeof(spacer) != 'undefined' ? spacer : '-'; // use '' to not add any spacer
		replace = typeof(replace) != 'undefined' ? replace : { '-47-' : '_' }; // use FALSE to not make any replacements

		// encode chars
		regxExclude = new RegExp( exclude, 'g' );
		s = s.replace( regxExclude, function( matched ){
			return spacer + matched.charCodeAt( 0 ) + spacer;
		});
		
		// replace some special chars
		if(replace)
		{
			for ( var i in replace )
			{
				regxReplace = new RegExp( i, "g" );
				s = s.replace( regxReplace, replace[i] );
			}
		}

		// add the prefix and return
		return prefix + s;
	}
	
	
	// idDecode converts an "idEncode" string back to it's original string
	//
	// Params:
	// "s" string to decode
	// "prefix" to be removed from the string
	// "spacer" the character that joins encoded items
	// "replace" object of strings to str.replace e.g. {"_" = "/"} replaces all "_" chars with a "/"
	//
	// Example:
	// id_http-58-__github-46-com_chris_project123_blob_master_new-95-mailer_install-45-file-46-rb
	// http://github.com/chris/project123/blob/master/new_mailer/install-file.rb
	
	function idDecode ( s, prefix, spacer, replace )
	{
		if(typeof(s) != 'string') return false;
		
		prefix = typeof(prefix) != 'undefined' ? prefix : 'id_';
		spacer = typeof(spacer) != 'undefined' ? spacer : '-';
		replace = typeof(replace) != 'undefined' ? replace : {'_' : '/'};
		
		spacerLength = spacer.length;
		
		// remove prefix
		s = prefix ? s.slice( prefix.length ) : s;
		
		// replace some special chars
		if( replace )
		{
			for ( var i in replace )
			{
				regxReplace = new RegExp( i, "g" );
				s = s.replace( regxReplace, replace[i]);
			}
		}
		
		// decode chars
		regxCharCode = new RegExp( spacer+'\\d+'+spacer, 'g' );
		s = s.replace( regxCharCode, function( matched ){
			return String.fromCharCode( parseInt( matched.slice( spacerLength, matched.length - spacerLength ) ) );
		});

		return s;
	}
	
	var string1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
	var string2 = "`-=~!@#$%^&*()_+{}[];:'\"?/><,.\\|";
	var string3 = "http://github.com/chris/project123/blob/master/new_mailer/install-file.rb";
	var string4 = '';
	
	var encode1 = idEncode(string1);
	var encode2 = idEncode(string2);
	var encode3 = idEncode(string3);		
	var encode4 = idEncode(string4);	
	
	var decode1 = idDecode(encode1);
	var decode2 = idDecode(encode2);
	var decode3 = idDecode(encode3);
	var decode4 = idDecode(encode4);
	
	console.log(string1);
	console.log(encode1);
	console.log(decode1);
	
	console.log(string2);
	console.log(encode2);
	console.log(decode2);
	
	console.log(string3);
	console.log(encode3);
	console.log(decode3);
	
	console.log(string4);
	console.log(encode4);
	console.log(decode4);
	

Why do you use return spacer + matched.charCodeAt( 0 ) + spacer;
rather than just spacer in idEncode function? Useful gist btw! :)