Escape all characters in a string using both Unicode and hexadecimal escape sequences

unicodeEscape.js

// Ever needed to escape '\n' as '\\n'? This function does that for any character,
// using hex and/or Unicode escape sequences (whichever are shortest).
// Demo: http://mothereff.in/js-escapes
function unicodeEscape(str) {
	return str.replace(/[\s\S]/g, function(character) {
		var escape = character.charCodeAt().toString(16),
		    longhand = escape.length > 2;
		return '\\' + (longhand ? 'u' : 'x') + ('0000' + escape).slice(longhand ? -4 : -2);
	});
}