Job offersCompaniesTestsBlogI'm an employerSign upLog in
fr
fr
Home>IT Tests>Questions>Java and Craftsmanship

25 interview questions on Java and Craftsmanshipfor developers (2026)

Test your technical skills before an interview of Java and Craftsmanship with 25 corrected questions. Beginner, Intermediate or Expert level.

or
Technology
Profession
Test
Sort by
Newest
Most popular
Last review
Filter by
Published
3919
To review
40
25 questions
Easy
5 votes767 runs
1 comment

Write a function that returns the first character of a string in Java

Back-end developer
strings
exceptions
Clément Devos (W3D Team)at Jan 24, 2022
Hard
4 votes546 runs
2 comments

This code allows to randomly get numbers between 1 to 31 in results. Should have declard SimpleDateFormat in the Thread.

Back-end developer
java
thread
date
Clément Devos (W3D Team)at Jan 24, 2022
Expert
1 vote653 runs
1 comment

Java code that replaces keys in a template with their values.

Back-end developer
java
map
string
Clément Devos (W3D Team)at Jan 24, 2022
Easy
1 vote528 runs0 comment

Write a Java code that returns the integer 51

Back-end developer
optional
map
filter
Clément Devos (W3D Team)at Jan 24, 2022
Medium
1 vote504 runs0 comment

Which Java 7 feature was only usable in Java 8?

Back-end developer
java
invoke dynamic
Clément Devos (W3D Team)at Jan 24, 2022
Hard
1 vote493 runs0 comment

A Java class that converts Arabic numbers to Roman numerals.

Back-end developer
java
recursion
map
Clément Devos (W3D Team)at Jan 24, 2022
Medium
1 vote488 runs1 comment

What is the output of the following code? ```java try { return 42; } finally { return 1337; } ```

Back-end developer
exceptions
return
Clément Devos (W3D Team)at Sep 19, 2022
Medium
1 vote488 runs0 comment

Write a Java implementation of the FizzBuzz code kata.

Back-end developer
java
fizzbuzz
Clément Devos (W3D Team)at Jan 24, 2022
Easy
1 vote321 runs1 comment

A code kata is a small exercice thought to train a certain development competence

Back-end developer
code kata
Clément Devos (W3D Team)at Feb 6, 2024
Easy
1 vote167 runs0 comment

What does SRP stand for?

Back-end developer
SOLID principles
Anonymous authorat Nov 26, 2024
Medium
1 vote162 runs0 comment

What is the name of the design pattern used to structure complex applications by considering the problem domain?

Back-end developer
Anonymous authorat Nov 26, 2024
Medium
0 vote534 runs0 comment

Which of these lines compile and would return true?

Back-end developer
strings
intern
Clément Devos (W3D Team)at Jan 24, 2022
Easy
0 vote507 runs0 comment

Immutability mainly allows to avoid side effects and to have thread-safe behaviours.

Back-end developer
java
immutability
Clément Devos (W3D Team)at Jan 24, 2022
Hard
0 vote503 runs0 comment

Write a thread safe singleton in Java

Back-end developer
singleton
thread-safety
Clément Devos (W3D Team)at Sep 19, 2022
Hard
0 vote497 runs0 comment

Explain why the second code compiles but the first one doesn't.

Back-end developer
exceptions
java
Clément Devos (W3D Team)at Jan 24, 2022
Medium
0 vote491 runs0 comment

Calculate 2.00 - 0.99 in Java

Back-end developer
floating point
Clément Devos (W3D Team)at Jan 24, 2022
Medium
0 vote484 runs0 comment

Improve the maintainability of this code by using polymorphism for items.

Back-end developer
java
polymorphism
Clément Devos (W3D Team)at Jan 24, 2022
Medium
0 vote483 runs0 comment

Compare two Java classes with the same fields and methods.

Back-end developer
java
class
record
Clément Devos (W3D Team)at Sep 19, 2022
Easy
0 vote479 runs0 comment

In Java, enums can have methods and attributes.

Back-end developer
enums
Clément Devos (W3D Team)at Jan 24, 2022
Medium
0 vote437 runs0 comment

Find the maximum age of employees in a mall.

Back-end developer
java
stream
flatmap
Clément Devos (W3D Team)at Jan 24, 2022