How to use Swift to convert a string containing a binary number to a hexadecimal number?

Question

Objective-C

How to translate a very long string like:
var str = "101010111111010101011"
into a hexadecimal number as a string "157EAB" ?

Answer 1

Split by 4 bits, translate by binary arithmetic. Easy to google, for example here stackoverflow.com/questions/19461478/convert-binar... .