equals and hashcodes method query

[Arjun Srivastava]

class Object2
{
int age;
String sex;
Object2(String sex,int age)
{
this.age=age;
this.sex=sex;
}
public String toString()
{
return "my age is "+age+"and sex is "+sex;
}
public String toString(int a)
{
return "hi this is how sting method is being overload"+a;
}


}
class Object1
{
    int age;
Object1(int age1)
{
age=age1;

}
public int getobjvalue()
{
return age;
}
public boolean equals(Object o)
{
if((o instanceof Object1) &&(((Object1)o).getobjvalue()==this.age))
return true;
else return false;
}
}
public class Main {

    public static void main(String[] args) {
    Object2 o=new Object2("male",20);
    System.out.println("o="+o+"\n"+o.toString(6));
    Object1 f=new Object1(20);
    Object1 k=new Object1(20);
    if(f.equals(k))
    {
        System.out.println("k=f"+"\n"+"k="+k.hashCode()+"\n"+"f="+f.hashCode());
    }
    } 
}

output:
o=my age is 20and sex is male
hi this is how sting method is being overload6
k=f
k=25669322
f=14978587


as we have learn if two objects are equal ,their hashcodes must be equal as well.

what i want to ask is : here two objects are equal i.e. k and f ,so why their corresponding hashcodes are coming different?

[Paul Clapham]

arjun srivastava wrote:as we have learn if two objects are equal ,their hashcodes must be equal as well.

That's right. The programmer is responsible for making that happen, by writing a hashCode() method which corresponds to the equals(Object) method.

what i want to ask is : here two objects are equal i.e. k and f ,so why their corresponding hashcodes are coming different?

Because the programmer didn't make that happen.

(And let me move this post to a suitable forum.)

[Arjun Srivastava]

ok
you mean to say hashcode() method must also overirde if we are overirding equals() method
then only we get the hashcodes equal for corresponding equal objects...?

otherwise ...NO

[Ernest Friedman-Hill]

Yes. If you override one of the two methods, you should override the other, too, and make sure they behave the way they're supposed to.

[David Newton]

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[Campbell Ritchie]

David Newton wrote:Please UseCodeTags . . .

. . . and indent your code correctly and completely, please.