Array.binarySearch returning wrong data

Question

I am trying to validate password and username using array and the array.BinarySearch function. The first two user names in the array: bradley and john are returning the correct

Answer 1

Your names array is not sorted:

String[] names = {"bradley","john","jim","clarke"};

which is a requirement of binarySearch() (and binary searching algorithm in general):

The range must be sorted into ascending order

Sort it first and it'll work like a charm:

String[] names = {"bradley","clarke","jim","john"};