JavaScript
Article

The jQuery titleCaps Function

By Sam Deering

I saw this function and thought I would share it as it could come in handy for dynamic generation of page titles (properly help with SEO if your titles are uniform and capitalized). The function was originally written by John Gruber but was ported over to jQuery by John Resig a couple of years ago.

Usage

var someVar = 'we love jquery';
console.log(upper(someVar));
//output: We love jquery

console.log(lower(someVar));
//output: we love jquery

console.log(titleCaps(someVar));
//output: We Love Jquery

The jQuery titleCaps Function

/**
 * Title Caps
 *
 * Ported to JavaScript By John Resig - http://ejohn.org/ - 21 May 2008
 * Original by John Gruber - http://daringfireball.net/ - 10 May 2008
 * License: http://www.opensource.org/licenses/mit-license.php
 */
(function($)
{
	var small = "(a|an|and|as|at|but|by|en|for|if|in|of|on|or|the|to|v[.]?|via|vs[.]?)";
	var punct = "([!"#$%&'()*+,./:;< =>?@[\\\]^_`{|}~-]*)";

	/**
	 * Apply title caps to the supplied string
	 * @param {String} title
	 * @returns {String}
	 */
	titleCaps = function(title)
	{
		var parts = [], split = /[:.;?!] |(?: |^)["Ã’]/g, index = 0;

		while (true)
		{
			var m = split.exec(title);

			parts.push( title.substring(index, m ? m.index : title.length)
				.replace(/b([A-Za-z][a-z.'Õ]*)b/g, function(all)
				{
					return /[A-Za-z].[A-Za-z]/.test(all) ? all : upper(all);
				})
				.replace(RegExp("\b" + small + "\b", "ig"), lower)
				.replace(RegExp("^" + punct + small + "\b", "ig"), function(all, punct, word)
				{
					return punct + upper(word);
				})
				.replace(RegExp("\b" + small + punct + "$", "ig"), upper));

			index = split.lastIndex;

			if(m) parts.push(m[0]);
			else break;
		}

		return parts.join("").replace(/ V(s?). /ig, " v$1. ")
			.replace(/(['Õ])Sb/ig, "$1s")
			.replace(/b(AT&T|Q&A)b/ig, function(all){
				return all.toUpperCase();
			});
	};

	function lower(word)
	{
		return word.toLowerCase();
	}

	function upper(word)
	{
	  return word.substr(0,1).toUpperCase() + word.substr(1);
	}
	
	//Examples
	var someVar = 'we love jquery';
	console.log(upper(someVar));
	//output: We love jquery
	console.log(lower(someVar));
	//output: we love jquery
	console.log(titleCaps(someVar));
	//output: We Love Jquery
})(jQuery);
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