A quick and dirty C#-like format function for js.

format.js

var format = function() {
  var args = Array.prototype.slice.call(arguments);
  var fmt = args[0];
  var vals = args.slice(1);
  return fmt.replace(/(?:^|([^{]))\{(\d+)\}/g, function(_, pref, i) {   
    pref = pref || '';
    return pref + vals[i];
  }).replace(/{{|}}/g, function(s) { 
    return s[0]; 
  });
};


// {n} is replaced by the n-th argument
format("Hi, my name is {0}", "John");
// => "Hi, my name is John"

format("Hello, {0} ({1}) {2}, nice to meet you.", "Brian", "Peter George St. John le Baptiste de la Salle", "Eno");
// => "Hello, Brian (Peter George St. John le Baptiste de la Salle) Eno, nice to meet you."

// Supports escaping as well
format("format() replaces all instances of {{n}} with the n-th argument");