Nice sprintf-Style placeholder replacement in format strings (only %s supported)

format.js

function format(format, a, b, c, d, e, f){
  
  if (format === undefined) {
    return "";
  }

  var idx = 0;
  var args = [a, b, c, d, e, f];
  
  return format.replace(/%s/g, function() { return args[idx++]; });
}

format("Key: %s, value: %s", "foo","bar") // "Key: foo, value: bar"

format2.js

function sprintf2(){
  
  if (arguments.length == 0) {
    return "";
  }

  var format = arguments[0];
  if (arguments.length == 1) {
    return format;
  }

  var idx = 0;
  var args = [].splice.call(arguments,1);
  
  return format.replace(/%s/g, function() { return args[idx++]; });
}

sprintf2("Key: %s, value: %s", "foo","bar") // "Key: foo, value: bar"