Returns a non-negative integer representing the Unicode code point at the given index If there is no element at that position, the result is undefined. If a valid UTF-16 surrogate pair does not begin at index, the result is the code unit at index.
codePointAt(index)
index
The zero-based index of the desired code point.
A number less in the range from 0 to 1114112.
If the index is out of bounds, returns undefined.
"ABC".codePointAt(1)
66