Lessons

In this lecture, you will learn how a programmer’s career is built: from the first steps to the Senior level, what salaries are common in the industry, how to choose a development path, what career branches exist, and why programmers are often happy and in demand. The material will help you understand how to plan your professional growth and what you can realistically achieve in 5 years in IT.

In this lecture, you will examine the problems of the old date and time APIs in Java ( java.util.Date, java.util.Calendar, java.text.SimpleDateFormat) and get acquainted with the modern, safe, and convenient java.time API (JSR‑310). You will understand the key advantages of immutable types, explicit time‑zone handling, formatting via DateTimeFormatter, and also learn how to convert between the new and legacy code. In the end, we will consider common mistakes and how to avoid them.

We break down the basic classes of the java.time package: LocalDate (date), LocalTime (time), and LocalDateTime (date+time). In practice, we’ll look at creating objects (current values and factory methods), parsing ISO strings, extracting components, add/subtract operations, comparison, as well as common mistakes and how to avoid them.

In this lecture we cover working with time and time zones in the Java 8+ API: what ZonedDateTime and Instant are, how to create a date/time in the required zone ( ZoneId), convert the same event between time zones via withZoneSameInstant(), obtain the absolute moment in UTC, and what pitfalls to expect during daylight saving time transitions. At the end — practical examples and common mistakes.

A practical guide to working with date and time in Java using the DateTimeFormatter class: standard ISO formats, custom patterns ofPattern, formatting and parsing, DateTimeParseException handling, and localized output (months and days of the week in the desired language).

In this lecture we explore working with time in Java: how to add and subtract intervals in LocalDate, LocalTime, LocalDateTime and ZonedDateTime, how to find differences with Period and Duration, compare dates using isBefore(), isAfter(), isEqual(), and also count exact units via ChronoUnit.DAYS.between(). We will discuss nuances of Instant and time zones and go over common mistakes.

In this article, you’ll learn how artificial intelligence has reshaped the IT job market: why the largest corporations are fighting for AI talent, what sums are being offered to top specialists, how the role of universities and open source is changing, and what it all means for everyday developers. Welcome to a new era where brains are the most valuable currency!

Autocomplete, templates, and refactoring. Learn how to write code at the speed of thought using Tab, Live Templates (psvm, sout), Postfix Completion, and formatting hotkeys.

In this lecture we’ll break down what a class and an object are in Java: a class as a “blueprint” and an object as an instance. We’ll learn to declare classes with the keyword class, add fields and methods, create objects using new, call methods like sayHello(), and use our own types ( Person, BankAccount) in code, including running via the main method.

In this lecture we break down what a Java class consists of: fields (state), methods (behavior), and constructors (initialization). We’ll talk about access modifiers public/ private, the this keyword, the default constructor, and also how to create objects with new, call methods like sayHello(), and avoid errors such as NullPointerException. Using the Person and User classes, we’ll see the full chain “fields → methods → constructors”.

In this lecture you will learn how to create objects in Java using the new keyword, how a constructor works, what is stored in a reference-type variable, and why trying to use null as an object leads to a NullPointerException. Using the Person class as examples, we will look at the syntax new Person(), method calls (for example, sayHello()), and common mistakes when creating instances.

In this lecture, we’ll examine constructor overloading in Java: why declare multiple constructors in one class ( Person, Account), how the compiler selects the right one by signature, and how to call one constructor from another via this(...) to eliminate duplication. We’ll show examples of creating objects with new, initialization options (owner, balance, currency), and cover common mistakes: missing no-arg constructor, parameter confusion, and this(...) call loops.