How do you hash a string to SHA512 in Swift?

Confused with Java Hash Set!!!!!!!!!!?

• 2. public class WrappedString { 3. private String s; 4. public WrappedString(String s) { this.s = s; } 5. public static void main(String[] args) { 6. HashSet<Object> hs = new HashSet<Object>(); 7. WrappedString ws1 = new WrappedString("aardvark"); 8. WrappedString ws2 = new WrappedString("aardvark"); 9. String s1 = new String("aardvark"); 10. String s2 = new String("aardvark"); 11. hs.add(ws1); hs.add(ws2); hs.add(s1); hs.add(s2); 12. System.out.println(hs.size()); } } What is the result? A. 0 B. 1 C. 2 D. 3 E. 4 F. Compilation fails. G. An exception is thrown at runtime we say that Hash set stores the unique values.. so i thought the size would be 1 but the size is 3. how is this possible?? can nyne xplain in detail??

• Answer:

  HashSet uses equals method to compare two objects before adding them. Since in the above code the Object's class equals method is not overriden in the WrappedString class the Object's class equals method is called and it consider ws1 and ws2 as different references hence it adds ws1, ws2 and s1 into the HashSet.