135 interview questions on Java for developers (2023)

Easy

7 votes1246 runs0 comment

How should a package be named in Java?

Full stack developer

Java

packages

Pierreat Sep 19, 2022

Hard

5 votes2276 runs0 comment

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

Back-end developer

Java

inheritance

package

Thomas De verdièreat Jan 4, 2022

Expert

5 votes2212 runs0 comment

Write a finalizer in Java.

Back-end developer

Java

finalizer

Thomas De verdièreat Dec 16, 2021

Medium

5 votes1261 runs1 comment

Write a Java program that prints 'welovedev'.

Full stack developer

Java

strings

variables

Pierreat Sep 19, 2022

Hard

4 votes2287 runs0 comment

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; } ```

Back-end developer

Java

loops

control flow

Thomas De verdièreat Dec 16, 2021

Hard

4 votes2250 runs1 comment

Serialization can be customized with the Externalizable interface

Back-end developer

Java

serialization

interface

Thomas De verdièreat Jan 4, 2022

Easy

4 votes2247 runs0 comment

What are the visibility modifiers for a method in Java?

Back-end developer

Java

access modifiers

methods

Thomas De verdièreat Jan 4, 2022

Hard

4 votes2217 runs1 comment

How to write a portable Java program

Back-end developer

Java

native

Thomas De verdièreat Jan 4, 2022

Hard

4 votes2196 runs0 comment

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

Back-end developer

Java

design pattern

tree

Thomas De verdièreat Jan 4, 2022

Medium

3 votes2245 runs0 comment

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

Back-end developer

Java

methods

Thomas De verdièreat Jan 4, 2022

Easy

3 votes2207 runs0 comment

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

Back-end developer

Java

string

Thomas De verdièreat Jan 4, 2022

Expert

3 votes2198 runs0 comment

A monitor in Java

Back-end developer

Java

thread

Thomas De verdièreat Jan 4, 2022

Hard

3 votes2191 runs0 comment

Autoboxing allows you to convert an int in Integer, a boolean in Boolean

Back-end developer

Java

autoboxing

Thomas De verdièreat Jan 4, 2022

Hard

3 votes2179 runs0 comment

What is the superclass of Integer, Long, Byte, BigDecimal and Short in Java?

Back-end developer

Java

superclass

Thomas De verdièreat Jan 4, 2022

Hard

3 votes2138 runs1 comment

What does the following code show?

Back-end developer

Java

variable

Thomas De verdièreat Jan 4, 2022

Easy

3 votes1235 runs1 comment

How to concatenate two strings of characters in Java?

Full stack developer

Java

strings

concatenation

Pierreat Jan 4, 2022

Hard

3 votes245 runs0 comment

The Garbage Collector G1(or Garbage First) is a GC that organizes the heap in a way

Back-end developer

Java

garbage collection

Loïcat Jan 31, 2022

Hard

2 votes2243 runs0 comment

A “synchronized” method

Back-end developer

Java

method

Thomas De verdièreat Jan 4, 2022

Hard

2 votes2228 runs0 comment

How to create a class in Java with a version number of 14.

Back-end developer

Java

class

Thomas De verdièreat Dec 3, 2021

Hard

2 votes2222 runs0 comment

Which of these statements corresponding to the Java language are true?

Back-end developer

Java

compile

interpret

Thomas De verdièreat Jan 4, 2022

135 interview questions on Javafor developers (2023)

Test your technical skills before an interview of Java with 135 corrected questions. Beginner, Intermediate or Expert level.

How should a package be named in Java?

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

Write a finalizer in Java.

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; } ```

Serialization can be customized with the Externalizable interface

What are the visibility modifiers for a method in Java?

How to write a portable Java program

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

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

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

A monitor in Java

Autoboxing allows you to convert an int in Integer, a boolean in Boolean

What is the superclass of Integer, Long, Byte, BigDecimal and Short in Java?

What does the following code show?

How to concatenate two strings of characters in Java?

The Garbage Collector G1(or Garbage First) is a GC that organizes the heap in a way

A “synchronized” method

How to create a class in Java with a version number of 14.

Which of these statements corresponding to the Java language are true?