63 interview questions for developers (2025)

14 votes1612 runs0 comment

Eric Hostaleryat Dec 3, 2021

11 votes775 runs0 comment

Samuelat Mar 28, 2022

9 votes793 runs0 comment

Samuelat Mar 28, 2022

9 votes629 runs0 comment

design pattern

8 votes1494 runs0 comment

Eric Hostaleryat Dec 3, 2021

6 votes776 runs0 comment

Samuelat Mar 28, 2022

5 votes1479 runs0 comment

Eric Hostaleryat Dec 3, 2021

5 votes1478 runs

Eric Hostaleryat Dec 3, 2021

4 votes1564 runs0 comment

design pattern

Eric Hostaleryat Sep 19, 2022

4 votes1530 runs0 comment

Eric Hostaleryat Dec 3, 2021

4 votes1437 runs1 comment

4 votes748 runs1 comment

operator overloading

Samuelat Mar 28, 2022

3 votes1527 runs0 comment

Eric Hostaleryat Dec 3, 2021

3 votes1502 runs0 comment

Eric Hostaleryat Mar 13, 2023

3 votes1476 runs1 comment

Eric Hostaleryat Dec 3, 2021

3 votes697 runs2 comments

Samuelat Mar 28, 2022

3 votes638 runs1 comment

access modifiers

Samuelat Mar 28, 2022

3 votes616 runs0 comment

Samuelat Mar 28, 2022

3 votes323 runs0 comment

polymorphism

encapsulation

Monemat Nov 3, 2023

2 votes1512 runs1 comment

Eric Hostaleryat Dec 3, 2021

63 interview questionsfor developers (2025)

Test your developer skills before an interview with 63 corrected questions on 80+ topics. Beginner, Intermediate or Expert level.

63 interview questionsfor developers (2025)

Test your developer skills before an interview with 63 corrected questions on 80+ topics. Beginner, Intermediate or Expert level.

Is the following code valid? class Person { constructor(name, age) { this.name = name; this.age = age; } } const person = new Person('John', 20); console.log(person.name); console.log(person.age);

Overrided method visibility must be the same or less restrictive than the inherited method.

Inheritance in OOP.

You need to develop a class for which there should be only one instance throughout your application. Which design pattern should you use for this?

Can we extend an abstract class in Java?

Can a class implements several interfaces ?

Is the following code valid? class Person { constructor(name, age) { this.name = name; this.age = age; } } const person = new Person('John', 20); console.log(person.name); console.log(person.age);

Is the following code valid? class Person { constructor(name, age) { this.name = name; this.age = age; } } const person = new Person('John', 20); console.log(person.name); console.log(person.age);

Which design pattern allows to dynamically add responsibilities to an object?

Is the following code valid? class Person { constructor(name, age) { this.name = name; this.age = age; } } const person = new Person('John', 20); console.log(person.name); console.log(person.age);

Can an interface inherit from another interface?

When can you do a+b in OOP ?

Is the following code valid? class Person { constructor(name, age) { this.name = name; this.age = age; } } const person = new Person('John', 20); console.log(person.name); console.log(person.age);

Implement the interface IEmailFormatter for the classes Person, Company, and ListOfPerson, which has a method GetEmailContent()

Implement the registration method on class A in a virtual way,Override the registration method on classes A1 and A2 when implementing these classes

Which modification of the following code WILL NOT make the output be "success" ?

What does the following code return ?

Explain the difference between overriding and overloading in OOP.

Inheritance, polymorphism and encapsulation

What is the default value of a field in a class in Java?