Covered Skills
Testing of these skills is covered in this pre-built test because they’re closely related. On our paid plan, you can easily create your own custom multi-skill tests.
Java
Java
The Java programming language is a simple, modern, general-purpose, object-oriented programming language. Having a basic familiarity with the programming language used on the job is a prerequisite for quickly getting up to speed.
Bug Fixing
Bug Fixing
Everyone makes mistakes. A good programmer should be able to find and fix a bug in their or someone else's code.
Language
Language
A programmer should use a language as a tool, always taking advantage of language-specific data types and built-in functions.
Exceptions
Exceptions
Exceptions exist in most modern programming languages, making it important for a programmer to understand them and know how to handle them.
Arithmetic
Arithmetic
Arithmetic is a fundamental branch of mathematics. An understanding of arithmetic concepts, and their application, is important for every candidate.
Java Spring
Java Spring
The Spring Framework is an application framework that can be used to build both java applications and web applications. As one of the most widely used frameworks it's important for most Java developers to have a working knowledge of.
MVC Pattern
MVC Pattern
The MVC pattern is designed to split an application into three logical parts: the model, the view and the controller. The model is responsible for the data and the rules of the application. The view is responsible for outputting that information, and the controller is responsible for accepting input from a user and forwarding it to the model or the view. Every web developer should be familiar with the MVC pattern and the benefits of encapsulating these components.
REST
REST
Representational State Transfer (REST) is a style of software architecture that defines a set of constraints to be used for creating Web services. As it is one of the most commonly used architectures, knowledge of REST is important for back-end developers.
Linked List
Linked List
A linked list is a linear collection of data elements where each element points to the next. It is a data structure consisting of a collection of nodes which together represent a sequence. It is usually used for advanced scenarios where we need fast access to the next element, or when we need to remove an element from anywhere in the collection.
OOP
OOP
Object-oriented programming is a paradigm based on encapsulating logic and data into objects, which may then contain fields and procedures. Many of the most widely used programming languages are based on OOP, making it a very important concept in modern programming.
Refactoring
Refactoring
The process of restructuring existing computer code without changing its external behavior. It is essential for keeping code readable and maintainable.
HashMap
HashMap
A HashMap (or dictionary) is a data type composed of a collection of key-value pairs, where each possible key appears at most once in the collection. It is used when we need to access items by their keys.
Iteration
Iteration
Iteration is the act of repeating a process, or cycling through a collection. Iteration is one of the fundamental flow control tools available to developers.
Lists
Lists
Lists are collections that act as dynamic arrays. Lists offer the flexibility of dynamically sized arrays, the simplicity of access of arrays, and are more performant than more ubiquitous collections in most scenarios.
Recursion
Recursion
A good programmer should be familiar with when to use recursive functions, since they can provide elegant solutions for complex problems.
Tree
Tree
A tree is a hierarchical structure defined recursively starting with the root node, where each node is a data structure consisting of a value, together with a list of references to other nodes (the "children"). A lot of problems can be solved efficiently with trees, which makes them important for developers.
Regex
Regex
A regular expression (regex) is a special text string for describing a search pattern. It is a common way for extracting data from text.
Strings
Strings
The string data structure is used to represent text. It is one of the most commonly used data structures. Therefore, every programmer should be skilled at string manipulation.
Accessibility Levels
Accessibility Levels
Access modifiers like public, protected, or private should be used to specify accessibility levels - who can access the object or some of its parts. They are one of the key points for writing maintainable object-oriented code.
ArrayList
ArrayList
The ArrayList class acts like a resizable array. It is used when there is a need for an array that can have a variable size.
Stream API
Stream API
Stream API is used to process collections of objects. It supports various methods, such as mapping, filtering, and sorting, which can be pipelined to produce the desired result. Since it simplifies code and improves productivity, it should be well known to Java programmers.
Class Modifiers
Class Modifiers
Class modifiers like abstract, final, or static should be used to specify how a class should be used and what is allowed or not allowed to be done with it. This is an essential topic for OOP programming.
Inheritance
Inheritance
In object-oriented programming, inheritance is the mechanism of basing a class upon another class, retaining similar implementation. Inheritance allows programmers to reuse code and is a must know topic for every programmer who works with OOP languages.
TDD
TDD
Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle: requirements are turned into very specific test cases, based on which the software is improved only in order to pass the new tests. TDD is an essential skill for modern programmers.
Dynamic Proxy Classes
Dynamic Proxy Classes
A dynamic proxy class is a class that implements a list of interfaces specified at runtime so that a method invocation through one of the interfaces on an instance of the class will be encoded and dispatched to another object through a uniform interface. Method invocations on an instance of a dynamic proxy class are dispatched to a single method in the instance's invocation handler to which parameters are passed that identify the method and the array of Object containing the parameters.
Method Overriding
Method Overriding
Method overriding, in object-oriented programming, is a language feature that allows a subclass to provide a specific implementation of a method that is already provided by one of its parent classes.
Integer Division
Integer Division
Integer division is division in which the fractional part (remainder) is discarded. Knowing this is important for optimal implementation of some algorithms and for avoiding common bugs.
Performance Tuning
Performance Tuning
The performance of an application or system is important. The responsiveness and scalability of an application are all related to how performant an application is. Each algorithm and query can have a large positive or negative effect on the whole system.
Random
Random
Random number generators are used to generate random numbers and/or symbols. There are a wide variety of random number generators each with very specific use cases, as such it's important for all developers to know and understand when to use each type.
Generics
Generics
Generics are a type or method that can operate on objects of various types while providing compile-time type safety. They can be used in generic classes to significantly reduce the amount of needed code.
Complexity
Complexity
A good programmer should be able to analyze and plan for the performance of an algorithm.
Stack
Stack
A stack is dynamic data container that follows the Last In First Out (LIFO) principle. Developers should use stack when the last item to be inserted into a container is the first one to be deleted from it.
Higher Order Function
Higher Order Function
A higher order function is a function that takes another function as an argument, or returns another function. Developers often use them for writing reusable code.
Interfaces
Interfaces
An interface is used to define an abstract type that defines behaviors as method signatures. Instances of different types can implement the same interface and provide a way for a developer to reuse the code.
Serialization
Serialization
Familiarity with data serialization to and from formats such as XML and JSON is important as it is commonly used for interprocess communication
XML
XML
Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The design goals of XML emphasize simplicity, generality, and usability across the Internet. This is one of the most used formats for exchanging data over the web.
Stream
Stream
A stream is a sequence of data elements made available over time. It is particularly useful for tasks that may benefit from being asynchronous, including tasks such as I/O processing or reading from a file, and as such is important for developers to understand.
Memory Management
Memory Management
Memory management allows programs to request memory dynamically from the operating system, and free it for reuse when no longer needed. Many modern programming languages automate this process; however, it should still be an important consideration when implementing an application.
Multithreading
Multithreading
Multi-threading allows a process to make more efficient use of modern hardware by allowing code to execute asynchronously. It can drastically improve the performance of any app; however, it can be tricky to get right, making this an important topic for any programmer.
Synchronization
Synchronization
When using multithreading, developers need to know how to make one thread wait for another to finish its task before continuing with its work.
Annotations
Annotations
Annotations are a form of syntactic metadata that can be added to source code. Annotations are often used by various frameworks to easily add functionality.
Spring Boot
Spring Boot
Spring Boot is Spring's convention-over-configuration solution for creating stand-alone, production-grade Spring-based Applications that can be "just run".
Configuration
Configuration
Configuration is a crucial component of most systems and frameworks. It allows a developer to tune performance and control access to features.
Database Abstraction
Database Abstraction
Database abstraction decouples business logic from a database, making it a key component of many web frameworks.
Spring Boot Actuator
Spring Boot Actuator
Spring Boot Actuator are a number of additional features that help with monitoring and managing Spring application.
Abstract Class
Abstract Class
An abstract class can include abstract methods and can be subclassed, but it cannot be instantiated. They are often used as building blocks of application.
Java Hibernate
Java Hibernate
Hibernate is an object-relational mapping tool for the Java programming language. It provides a framework for mapping an object-oriented domain model to a relational database. Hibernate handles object-relational impedance mismatch problems by replacing direct, persistent database accesses with high-level object handling functions.
HQL
HQL
The Hibernate Query Language is a powerful query language that is similar in appearance to SQL. It is fully object-oriented and allows concepts like inheritance, polymorphism, and association. It’s very commonly used for queries with Hibernate.
Entity Type
Entity Type
The entity type describes the mapping between the persistable domain model object and a database table row.
Insert
Insert
Even though most database insert queries are simple, a good programmer should know how to handle more complicated situations like batch inserts.
Aggregation
Aggregation
An aggregate function is typically used in database queries to group together multiple rows to form a single value of meaningful data. A good programmer should be skilled at using data aggregation functions when interacting with databases.
Test Case Design
Test Case Design
Being able to create a set of test cases that ensure adequate test coverage is a key skill for creating a successful test. It is desirable for the test suite also to be optimal, i.e. to minimize test execution effort and time without affecting the test coverage.
Unit Testing
Unit Testing
Unit testing is a type of software testing where individual units or components of a software are tested. Unit testing of software applications is done during the development (coding) of an application and should be well known practice to any developer.
Algorithmic Thinking
Algorithmic Thinking
When designing and/or analyzing an algorithm or data structure, it is important to consider the performance and structure of an implementation. Algorithmic thinking is one of the key traits of a good programmer, especially one working on complex or performance-critical code.
Queue
Queue
A queue is a collection of items that are maintained in a sequence and can be modified by the addition of entities at one end of the sequence and removal from the other end of the sequence. It is the collection to be used when first-in-first-out (FIFO) collection is needed.
Data Structures
Data Structures
Choosing the right data structure to solve a problem can have huge implications on the performance of an application. Knowing when to use a specific data structure is one of the most important skills for a programmer.
Sorting
Sorting
Every programmer should be familiar with data-sorting methods, as sorting is very common in data-analysis processes.
Graphs
Graphs
Many real-life situations are best modeled by graphs. Therefore, an in-depth knowledge of graph data structures is important for a good programmer.
Dynamic Programming
Dynamic Programming
Dynamic programming methods for code optimization can be very useful to a programmer who understands them.
HashSet
HashSet
HashSet is container that stores unique elements in no particular order. This allows for fast checks to see if a value was already added.
Arrays
Arrays
An array is a container of a fixed number of objects of a similar type. It is a fundamental component of most programming languages.
StringBuilder
StringBuilder
Since a string is an immutable data structure, concatenating multiple strings can introduce significant performance penalties. Every experienced developer should know when to use StringBuilder instead of simply concatenating two strings to improve performances in such scenarios.
Recommended Job Roles
These are the job roles that we recommend for the Java, Hibernate, and Spring Boot online test.
Back-End Developer
Spring Framework Developer