format.js

//format('hello {0}!', 'world') => 'hello world!'
//format('hello {0}!{1}', 'world', 'OK') => 'hello world!OK'
//format('hello {0}!', ['world']) => 'hello world!'
//format('hello {0}!{1}', ['world', 'OK']) => 'hello world!'
function format(str){
	var dataList = (/array/i).test(Object.prototype.toString.apply(arguments[1])) ? arguments[1] : Array.prototype.slice.apply(arguments, [1]);
	return str.replace(/\{(\d+)\}/g, function(target, index){
		index = parseInt(index, 10);

		return dataList[index] || '';
	});
}