I am not able to understand this java program

Question

What is the output of bellow code ?
public class Bean{
    private String str;
    Bean(String str ){
        this.str = str;
    public String getStr() {
        return str;
    public boolean equals(Object o){
        if (!(o instanceof Bean)) {
            return false;
        return ((Bean) o).getStr().equals(str);
    public int hashCode() {
        return 12345;
    public String toString() {
        return str;
import java.util.HashSet;
public class Test {
    public static void main(String ... sss) {
        HashSet myMap = new HashSet();
        String s1 = new String("das");
        String s2 = new String("das");
        Bean s3 = new Bean("abcdef");
        Bean s4 = new Bean("abcdef");
        myMap.add(s1);
        myMap.add(s2);
        myMap.add(s3);
        myMap.add(s4);
        System.out.println(myMap);
}(Choose correct one from multiple bellow)
1) das abcdef
2) das abcdef das abcdef
3) das das abcdef abcdef
4) das
What i understand is that the following constructor
Bean(String str ){
        this.str = str;
    }is used to initialize the instance variable
private String str;then we have overridden the equals method, in this method we first check if o is not an instance of Bean class whereby we return false
then we are calling getStr() and equals(str)
return ((Bean) o).getStr().equals(str);the getStr() method is going to return the instance variable we initialized. SO we will be having something like
str.equals(str) Here I am not clear what is going to be the output. Please explain in detail

Answer 1

1. [das, abcdef]
map create a pair key - value, similar to Dictionary.
"Hash map structures consist of an internal array where elements are stored. Since the internal storage is an array, clearly there must be a mechanism for determining an index into the array for an arbitrary key. In fact, the mechanism needs to give an integer index value which is smaller than the size of the array. This mechanism is called the hash function. In Java hashed based Maps, the hash function converts any object into an integer that fits into the internal array. You don't have to look hard to find an easily available hash function: every object has a hashCode() method which returns an integer value. To map that value into any array, it is sufficient to convert it to a positive value and take the remainder after dividing by the array size. "
you will get the same hashcode for the same value!