Constructing an ES6 class by name (from a string) [duplicate]

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• create new javascript object from variable 3 answers

I'm using ES6 classes and would like to be able to construct instances 'dynamically' based on strings. Here's a quick example:

class Foo { }
class Bar { }

const className = 'Foo';
const classInstance = createInstance(className); 

... where createInstance constructs the class indicated by the supplied string.

Any ideas?