interpolate.js

//	a string interpolator, extending the String object,
//	returns a new string with the values in the curly braces replaced
//	with the ones provided by a passed object.

String.prototype.interpolate = function(obj) {
	var buf = this;
	for(x in obj) {
		var re = new RegExp("{"+x+"}","g");
		buf = buf.replace("{"+x+"}", obj[x]);
	}
	return buf;
}

var str = "My name is {name}, and I'm {age} years old";
str.interpolate({name: "Michael", age: 27}); // "My name is Michael, and I'm 27 years old"