Is it possible to define a 2 dimensional set in Javascript, which could look as follows:
let set = {}{};
and then to access this like a 2 dimensional array as set[][]; ?
By the way, an Array is not suitable for my purpose, because I need to index with strings instead of numbers.
What you're describing doesn't seem like sets, you seem to be talking about an object whose values are other objects, e.g.
let set = {
a: {x: 1, y: 2},
b: {x: 10, y: 15}
}
You can then access this as set.a.x or set['b']['y']
key: value pairs. You can do let set = {a: {}, b: {}}. You can also just do let set = {} and you can add properties as needed like set['a'] = {}