Thread: Won't display its Location for Linear Searching.

So Im trying to display the location for the odd number which is 31. But it won't display the location of it.
as you see in the code. Im using bluej there's no error in compiling it's just i feel there's something missing with the location. I can't pin point what is it..

import java.util.*;
import java.io.*;
import java.util.Arrays;
import org.apache.commons.lang.ArrayUtils;
 
public class NumberTestingWithSearching
{
    public static void main(String[]args)
    {
      int[] Numbers = new int[] {10,41,21,24,34,15,40,12,32,23,13,25,30,31,22,33,14,35,20,11};
      List<Integer> oddarr = new ArrayList<Integer> ();
      List<Integer>evenarr = new ArrayList<Integer>();
 
      int[] OddSearch = {31};
      int EvenSearch = 32;
 
      //organizing Even and Odd Numbers
       System.out.printf("Numbers: ");
       for (int a: Numbers){
 
         if ((a & 1 ) == 1){
             oddarr.add(a);
           }
         else {
             evenarr.add(a);
 
        }
        System.out.printf(" "+a);
             }   
      System.out.println();
      System.out.println("Odd Numbers : " +oddarr);
      System.out.printf("Even Numbers : " +evenarr+"\n\n");
 
      //Converting Thing
      Integer[] OddNumsearch = oddarr.toArray(new Integer[oddarr.size()]);
      int[] OddArrInt = ArrayUtils.toPrimitive(OddNumsearch);
      System.out.println(Arrays.toString(OddArrInt));
      System.out.println();
 
      //Linear Search Testing
      for (int b = 0; b < OddArrInt.length;b++){
 
        if (OddArrInt==(OddSearch)){
           System.out.println("Linear Search Location for Number 31 :"+OddArrInt);
                }
 
      }
 
      //Sorting Even numbers properly
      Collections.sort(evenarr);
      System.out.println("Sorted Even Numbers: "+evenarr);
 
 
    }
}

What's the purpose of this line:

int[] OddSearch = {31};

Compatibility with the converted int since int[] and int is not comparable types so i made it an array for it to be equal
and the number that its trying to search which is 31.

if (OddArrInt==(OddSearch)){
           System.out.println("Linear Search Location for Number 31 :"+OddArrInt);
                }

Please follow Java's naming conventions: variable and method names should begin with lowercase letters. Class names begin with uppercase letters. Not following these conventions makes reading your code difficult.

Why don't you just search the array Numbers (should be named 'numbers') for the int value 31 as in:

if ( numbers[i] == 31 ) ?

I don't think this condition:

if (OddArrInt==(OddSearch))

will ever be true.

because the numbers are being separated with 2 var which is the odd array and even array, to separate the odd and even numbers and I'm trying to search the numbers in the odd array specifically.
I research online that i'd need to convert the arraylist into primitive int so the program could search the number 31 and display its location. So i sorta made the odd number search into an array for compatibility.

That's what im trying to solve and i have a feeling something's missing.

You have one int[] Array and 2 ArrayList<Integer>s. All 3 of those collections can be iterated and searched for a desired value to return the index of that value with few significant differences in technique. In fact, if you're familiar with the enhanced for loop, the mechanics of iterating all 3 collections would be virtually the same. ArrayList even has a method indexOf() that further simplifies the task. If you can't use the enhanced for loop or indexOf(), then simple modifications to a regular for loop would accomplish the same iterations.

What you're doing - even though I don't understand it - is adding unnecessary complication and, as you've already discovered, doesn't provide the desired results.

is there an example of using them the index i mean? Because before I used arraylist i actually use the normal int odd = new int[]; but didn't like putting limit numbers so i switched to arraylist.

I'm not sure what you're asking, and I don't know what "didn't like putting limit numbers" means. Ask a specific question: "How do I iterate an ArrayList and find the desired index?" might be what you mean, but I'm not sure, and I don't like guessing.

yea the "How do I iterate an ArrayList and find the desired index?"

Here are examples:

import java.util.*;
 
// demonstrates finding values in an ArrayList using indexOf() and iteration
public class TestClass3
{
    public static void main( String[]args )
    {
        // your array of numbers and a single ArrayList of Integers
        int[] numbers = new int[] {10, 41, 21, 24, 34, 15, 40, 12, 32, 23, 13, 25, 30, 31, 22, 33, 14, 35, 20, 11};
        List<Integer> arrayListOfNumbers = new ArrayList<Integer>();
 
        // add each primitive to the ArrayList
        for ( int integer : numbers )
        {
            arrayListOfNumbers.add( integer );
        }
 
        // finding the index of 31 without iteration
        int indexOfTarget = arrayListOfNumbers.indexOf( 31 );
 
        System.out.println( "Index of 31 in array list without iteration = " +
            indexOfTarget );
 
        int i = 0;
 
        // finding the first index of 31 in the ArrayList using iteration
        for ( Integer integer : arrayListOfNumbers )
        {
            // try this without the intValue() method )
            if ( integer.intValue() == 22 )
            {
                indexOfTarget = i;
                break;
            }
 
            // increment the index (or a regular for loop could be used)
            i++;
        }
 
        System.out.println( "Index of 22 in array list with iteration = " +
            indexOfTarget );
 
    } // end method main()
 
} // end class TestClass3

Thanks I'll give it a try.