Promotion
CodeGym University
Learning
Course
Tasks
Surveys & Quizzes
Games
Help
Schedule
Community
Users
Forum
Chat
Articles
Success stories
Activity
Reviews
Subscriptions
Light theme
Authors
Reviews
About us
Start
Start learning
Start learning now
Articles
Authors
All groups
All Articles List
John Selawsky
Senior Java Developer and Tutor at
LearningTree
Write a message
A senior Java developer and Java tutor at Learning Tree International programming courses. Sometimes I write some stupid programming stuff about Java. 7 years experience of Java/J2EE development. In Java We Trust.
Author's articles
John Selawsky
Stream API
20 September 2023 12:43
Java Stream.of() method
You've probably already heard that streams in Java are designed to process data. They represent a sequence of elements that can be processed using various operations such as...
John Selawsky
Java Arrays
10 May 2023 13:15
String Array in Java
Often the first data structure a novice programmer gets acquainted with is an array. That's because arrays are fairly easy to learn. A one-dimensional array is a sequence that consists of a fixed number of cells in which data can be stored. In the case...
John Selawsky
Methods in Java
11 January 2023 12:26
Methods in Java
Hello again! In the last lesson we got acquainted with classes and constructors, and learned how to create our own. Today we will become better acquainted with methods, an essential part of classes. A method is a set of commands which allow you to perform a specific operation in a program ...
John Selawsky
Java Developer
1 December 2022 15:00
A* Search Algorithm in Java
Different search algorithms are tailored for different tasks. Today we are going to talk about A* search, one of the most effective pathfinding algorithms. This one is very well suited for computer games and building searching graphs such as ways between cities and so on.
John Selawsky
Design Patterns in Java
15 September 2022 10:59
Strategy Design Pattern
Hi! In previous lessons, we've already briefly become acquainted with the concept of inheritance. In case you forgot, I'll remind you that this term refers to a standard solution to a common programming task. At CodeGym, we often say that you can google the answer to almost any question...
John Selawsky
Java Developer
29 August 2022 7:29
XML in Java
Hi! Today we will introduce another data format called XML. This is a very important topic. When working on real Java applications, you will almost certainly encounter XML-related tasks. In Java development, this format is used almost universally (we will find out why below), so I recommend...
John Selawsky
Java Algorithms
15 August 2022 8:00
Bubble sort Java
In this article the bubble sort algorithm is described. It is the easiest sorting algorithm to learn, so every software developer knows it. This algorithm is usually used for learning purposes or you may get it as a task in your Java Junior Interview. Bubble sort algorithm is very easy to understand, however it is not...
John Selawsky
Statements in Java
19 July 2022 13:09
IF ELSE Java Statements
An if else statement in Java is a conditional statement. Java uses conditions just like mathematics, allowing comparisons that yield Boolean results. So you can test inputs to see how they compare to a static set of values that you specify. Because the result is Boolean, there are only two possible results...
John Selawsky
Strings in Java
14 July 2022 10:43
Substring in Java
This article is about substring () methods in Java language. Here you will find the explanation of how using these methods, find out how they work and get some beneficial examples. Substring in general is a contiguous sequence of characters inside the String. It could be a part of the String or the whole String as well...
John Selawsky
Java Exceptions
9 June 2022 8:32
Java Catch Multiple Exceptions
Before learning about catching multiple exceptions, you need to be familiar with basic exception handling in Java. Moving forward, we assume you are familiar with a try and catch block in Java...
John Selawsky
Java Numbers
29 March 2022 7:35
How to Convert long to int in Java
In this article we are going to explain how to convert long to int in Java and write some code examples. Since long is a larger data type than int, here we should use type casting for such conversion...
John Selawsky
Java Collections
23 March 2022 12:01
How to update the value of an existing key in HashMap
You know that there is always a key and a value in HashMap or any other Map. Key is called a key for a reason, because you get the access to values by the key. The key is unique...
Show more
1
2
3
Please enable JavaScript to continue using this application.