Question

I just got a homework assignment, and it’s just creating a linear search algorithm in java. However, I also want to make this code work with any data type like Strings, ints, doubles, etc and different kinds of containers like arrays, hashsets, lists, and collections, so I won’t have to waste so a lot of extra lines to overload the method. Here’s the current code.

public class Search
{
    public int linear (Object[] contents, Object query)
    {
        for (int index = 0; index < contents.length; ++index)
        {
            if (query.equals(contents[index]))
            {
                return index;
            }
         }
         return -1;
    }
}

However, in my other class, for testing, I have an int array and an int to search for. I get an error that says “The method linear(Object[], Object) in the type Search is not applicable for the arguments (int[], int)”

Answer 1

int is not an object, it’s a primitive. you may user Integer[]. Better yet, you should use generics. You may also want to use list instead of array (just a thought): I show both below.

import java.util.List;
public class LinearSearch<E>
{
public int linear (E[] contents, E query)
{
    for (int index = 0; index < contents.length; ++index)
    {
        if (query.equals(contents[index]))
        {
            return index;
        }
     }
     return -1;
}

public int linear (List<E> contents, E query)
{
    for (int index = 0; index < contents.size(); ++index)
    {
        if (query.equals(contents.get(index)))
        {
            return index;
        }
     }
     return -1;
}
}