Question

I am using the Java 2 Platform to practice different algorithms. I am getting two errors and I think the first one is that I am passing the integer “5” from arrayList[] and getting an error. The second problem is that I am getting an error in the main method when I call binarySearch();. Do I need to put arrayList as the parameter for binarySearch(arrayList)? Any help would be appreciated.

import java.util.ArrayList;

public class BinarySearch {

 int arrayList[]={1,2,3,4,5,6,7,8,9};

 public static int binarySearch(int[] arrayList[],int 5)
 {
  int low = 0;
  int high = arrayList.length - 1;
  int mid = 0;

  while(low<=high)
  {
   mid = (low+high)/2;
   if(arrayList[mid].compareTo(searchObj)<0)
    low = mid + 1;
   else if (arrayList[mid].compareTo(searchObj)>0)
   {
    high = mid -1;
   }
   else 
    return mid;
  }
  return -1;

 }
 public static void main(String args[])
 {
  binarySearch();

 }

}

Answer 1

At the point of declaration of the BinarySearch method you need this:

  public static int binarySearch(int[] arrayList,int searchObj){

     ///rest of your method

That is, you are searching for searchObj in the arrayList.

Then to call the method you provide the value for arrayList and searchObj. Like this:

 binarySearch(arrayLIst, 5);