What characters are grouped with Array.from?

Question

I\'ve been playing around with JS and can\'t figure out how JS decides which elements to add to the created array when using Array.from(). For example, the followin

Answer 1

UTF-16 (the encoding used for strings in js) uses 16bit units. So every unicode that can be represented using 15 bit is represented as one code point, everything else as two, known as surrogate pairs. The iterator of strings iterates over code points.

UTF-16 on Wikipedia