K&B SCJP 5 Study Guide p628 problem 9

[Harry Henriques]

I don't know how to search for a solution to this problem. I'm sure that this question has been asked before.

9. Given a properly prepared String array containing five elements, which range of results could a proper invocation of Arrays.binarySearch() produce.

Answer:

int[] arr = new int[5];
arr[0] --> 0 or -1
arr[1] --> 1 or -2
arr[2] --> 2 or -3
arr[3] --> 3 or -4
arr[4] --> 4 or -5
after arr[4] --> -6
answer -6 through 4

Is this correct?

[Ankit Garg]

Here's a bit of searching I did using the search query "K B binarySearch"

https://coderanch.com/t/436980/Programmer-Certification-SCJP/certification/binarysearch-method
https://coderanch.com/t/270611/Programmer-Certification-SCJP/certification/Chap-pg-from-kathy-Sierra
https://coderanch.com/t/266974/Programmer-Certification-SCJP/certification/Arrays-binarySearch-query

HTH

[Harry Henriques]

C:\Documents and Settings\Harry Henriques>java BinarySearch
int [] ia = new int []{ 2, 4, 6, 8, 10 };
insert 1 at index 0 is -1
ia[0] = 2 at index 0
insert 3 at index 1 is -2
ia[1] = 4 at index 1
insert 5 at index 2 is -3
ia[2] = 6 at index 2
insert 7 at index 3 is -4
ia[3] = 8 at index 3
insert 9 at index 4 is -5
ia[4] = 10 at index 4
insert 11 at index 5 is -6

import java.util.*;
class BinarySearch {
        public static void main( String [] args ) {
                int [] ia = new int []{ 2, 4, 6, 8, 10 };
                Arrays.sort( ia );
System.out.println("int [] ia = new int []{ 2, 4, 6, 8, 10 };");
System.out.println("insert 1 at index 0 is "+Arrays.binarySearch(ia, 1));
System.out.print("ia[0] = ");
System.out.println("2 at index "+Arrays.binarySearch(ia, 2));
System.out.println("insert 3 at index 1 is "+Arrays.binarySearch(ia, 3));
System.out.print("ia[1] = ");
System.out.println("4 at index "+Arrays.binarySearch(ia, 4));
System.out.println("insert 5 at index 2 is "+Arrays.binarySearch(ia, 5));
System.out.print("ia[2] = ");
System.out.println("6 at index "+Arrays.binarySearch(ia, 6));
System.out.println("insert 7 at index 3 is "+Arrays.binarySearch(ia, 7));
System.out.print("ia[3] = ");
System.out.println("8 at index "+Arrays.binarySearch(ia, 8));
System.out.println("insert 9 at index 4 is "+Arrays.binarySearch(ia, 9));
System.out.print("ia[4] = ");
System.out.println("10 at index "+Arrays.binarySearch(ia, 10));
System.out.println("insert 11 at index 5 is "+Arrays.binarySearch(ia, 11));
        }
}    

[Ankit Garg]

Is this a question?? You didn't write anything apart from the code and the output...

[Harry Henriques]

Ankit Garg wrote: Is this a question?? You didn't write anything apart from the code and the output...

Ankit, I looked at the links that you provided, but the answers to my question weren't easy for me to understood. I thought that I could provide a better answer to my own question, and I tried to do so with this example code and output. Maybe this code snippet will help someone else.

Harry