7) Suppose there is Student class like

class student {
int age;
string name;
}

We want to store these objects in a HashMap. Do we need to
override any methods in Student class? If any which ones
and why? what if i just override equals or just hashcode?
what will be the results in both the cases?




Answers were Sorted based on User's Feedback



7) Suppose there is Student class like class student { int age; string name; } We want to s..

Answer / manoranjan

Logically no need to override any method but problem with
this design will be that we can not find the objects stored
in the hashmap. So to overcome this problem we need to
override equlas() and hashcode() mathod of Object
class.According to Sun java guide line if equals() method is
teeling that two objects are equal then their hashcode must
be same.But reverse is not true.

Is This Answer Correct ?    10 Yes 0 No

7) Suppose there is Student class like class student { int age; string name; } We want to s..

Answer / lucky singh

It is a good practice to override equals() and hashcode()
methods if you are dealing with collections. Both of the
functions are used while searching for a particular object
in a hashmap. In general, equals() method is used to
determine if two objects are meaningfully equal or not. And
hashcode() method is used to determine if two objects are
meaningfully unequal or not.

Is This Answer Correct ?    2 Yes 0 No

7) Suppose there is Student class like class student { int age; string name; } We want to s..

Answer / krishna

There is no need to override equals() and hashCode() methods. But if we want to eliminate duplicate objects in the HashMap, you should override both the methods. Either one is not enough.

Is This Answer Correct ?    0 Yes 0 No




7) Suppose there is Student class like class student { int age; string name; } We want to s..

Answer / punch

Their is NO need to override any methods of student class,
bcoz in the ket of hashmap we are using String and equal
method and hashcode method of String class is already
overrided . So NO need to override any methods and take help
of String class of the same.

Is This Answer Correct ?    1 Yes 7 No

Post New Answer



More Core Java Interview Questions

Difference between error and exception

3 Answers   TCS, Nous,


What are "class access modifiers" in Java?

0 Answers   Genpact,


What is runtime polymorphism or dynamic method dispatch?

0 Answers  


how do you store phone numbers using java collections

5 Answers   Bosch, IBAB,


What is the implementation of destroy method in java. Is it native or java code?

0 Answers  






what is the difference between static block and static method

19 Answers   Huawei,


What is static binding and where it occurs?

4 Answers  


Explain java code for recursive solution's base case?

0 Answers  


Why char array is favored over string for the storage of passwords?

0 Answers  


What’s the difference between the methods sleep() and wait()?

0 Answers  


Can I override protected method in java?

0 Answers  


how to run ecllipse with jettyserver for windows environment using batch file

0 Answers  






Categories