158 interview questions on Java for developers (2026)

38 votes3312 runs

Pierreat Sep 19, 2022

17 votes3651 runs

control flow

Thomas De verdièreat Dec 16, 2021

17 votes3207 runs

Pierreat Sep 19, 2022

15 votes1960 runs

14 votes3662 runs1 comment

serialization

Thomas De verdièreat Jan 4, 2022

14 votes3590 runs0 comment

Thomas De verdièreat Jan 4, 2022

14 votes3544 runs0 comment

Thomas De verdièreat Jan 4, 2022

14 votes3484 runs0 comment

Thomas De verdièreat Dec 16, 2021

13 votes3641 runs

serialization

Thomas De verdièreat Dec 2, 2021

12 votes3682 runs0 comment

Thomas De verdièreat Jan 4, 2022

11 votes3640 runs0 comment

Thomas De verdièreat Jan 4, 2022

11 votes3533 runs0 comment

design pattern

Thomas De verdièreat Jan 4, 2022

11 votes3050 runs

concatenation

Pierreat Jan 4, 2022

10 votes3105 runs0 comment

Pierreat Jan 4, 2022

9 votes3453 runs0 comment

Thomas De verdièreat Jan 4, 2022

9 votes3432 runs2 comments

Thomas De verdièreat Jan 4, 2022

9 votes3129 runs0 comment

Pierreat Sep 19, 2022

8 votes3625 runs0 comment

Thomas De verdièreat Dec 16, 2021

8 votes3493 runs0 comment

Thomas De verdièreat Jan 4, 2022

8 votes3437 runs0 comment

Thomas De verdièreat Jan 4, 2022

158 interview questions on Javafor developers (2026)

Test your technical skills before an interview of Java with 158 corrected questions. Beginner, Intermediate or Expert level.

158 interview questions on Javafor developers (2026)

Test your technical skills before an interview of Java with 158 corrected questions. Beginner, Intermediate or Expert level.

Write a Java program that prints 'welovedev'.

How many times is the condition `(a++ < 15)` evaluated in the following code? ```java int a = 3; while (a++ < 15) { if ((a++ % 5) == 0) break; } ```

How should a package be named in Java?

What is the difference between an interface and an abstract class in Java?

Serialization can be customized with the Externalizable interface

A monitor in Java

What does the final keyword mean in front of a method in Java?

How many instance of Integer cannot be freed from memory?

What is the error message when you try to serialize a class that does not implement Serializable?

A Customer class has the com.company.model package.

A “synchronized” method

What "design pattern" makes it possible to offer a means of treating the elements of a tree without worrying about the course?

How to concatenate two strings of characters in Java?

Add elements to an ArrayList in Java

Which of these classes is the most suitable for composing a character string from several elements concatenated to each other?

What does the following code show?

Are arrays primitives types in Java?

Write a finalizer in Java.

What is the classpath for?

Java 5: where to place the "@Override" tag and why?