What about equals() and hashCode()? - Cracking the Java Coding Interview

Показать описание

Cracking the #Java #Coding #Interview - Question 10: What about equals() and hashCode()?

Рекомендации по теме

Комментарии

please don't use the background music. also, please improve the audio quality as it's not easier to hear with full volume sometimes.

ankit-gupta

Yes background music is higher than the actual voice.

davidprasad

Or even better: Use records and have the JVM automatically provide appropriate equals() and hashCode() implementations.
Implementing hashCode() and equals() explicitly should probably be considered a code smell in Java 16+ (under most circumstances anyway).

jay_sensz

The typical hashCode() (* 31 +) implementation generates lots of clashes. This is true for hash code generated with your IDE or if you use a record. My advice is:

1. Whenever implementing hashCode() and equals(), also /always/ implement Comparable. This is your safety in case you have a poor hash code and end up with many keys in the same bucket. HashMap Java 8+ can then create a red-black tree for you. This is true whether you use Lombok, records, your IDE, or hand-write your hashCode() method.

2. Try and write as "perfect" a hashCode() method as possible. Take a moment to think about the possible values and how you can make them as distinct as you can. Spreading out the numbers is not that important.

3. Lastly, try and make the hashCode() as numerically small (above 0) as possible.

Do this, and you will typically get a factor 3x speedup over what the IDE and records generate.

heinzkabutz

Sir please don't use BGM..also improve the audio quality so that we can clearly grasp knowledge which is given by you..

umasingh

Why does using an IDE get a bulletpoint?

tylerbakeman

Tbh, these simple ones are never asked in interviews....

cccc

Please. Never ever use the background music again. And increase your voice volume. There must be some production person at Oracle who can do this for you.

redorange

What about equals() and hashCode()? - Cracking the Java Coding Interview

02. Equals and HashCode Contract & Different Variations

#58 Object Class equals toString hashcode in Java

What about equals() and hashCode()? - Cracking the Java Coding Interview

Equals and Hashcode Contract in Java [Important Java Interview Question] | Code Decode

.equals() vs. == in Java - The Real Difference

Die equals() und hashCode() Methode | Java Tutorial für Fortgeschrittene

Java - Compare the Objects using equals() & hashCode()

Overriding equals and hashCode in Java - 039

Interview Experience of Publicis Sapient | Java interview Live !!

18. What is equals() & hashCode() & why to override equals() & hashCode() | Kotlin Compl...

Why we should override equals and hashCode methods in our class | Pradeep Nailwal

HashCode and Equals | Java Placement Course | Lecture 51

What is hashcode() and equals() contract? #java #interview #interviewtips

what will happen if don't override the equals method | java interview question

Java. Методы equals и hashCode.

Java equals and hashcode

Why is it important to override the hashCode and equals method of Object class in Java?

hashcode() in java || The IMPACT of hashcode and equals || java object class || Part 1

The equals hashCode Contract - Java Programming

Equals and hashcode contract

Generation of toString()/equals()/hashCode() implementations | JPA Buddy

Java interview question on hashcode() and equals() || Java collection interview questions on HASHMAP

equals and hashcode contract in Java

Equals and Hashcode Contract in Java [Important Java Interview Question] | @JavaExpress