Lectures

In this article, you’ll learn why programming is accessible to everyone, what advantages the programmer profession offers, how the innovative learning approach on JavaRush is different, and why practice matters more than theory. This material will inspire you to believe in yourself and start your journey in IT!

In this lecture we will go over the basics of functions in Kotlin: how to declare functions using fun, how to call them from main, how parameters differ from arguments, how the return type is specified ( Int, String, Double, Boolean), and why a function signature is a contract. At the end we will build a mini app, a “step tracker”, and discuss typical beginner mistakes.

In this lecture, we break down how function completion via return works in Kotlin: why the compiler requires a value to be returned on all execution paths, how to use early return (guard clause) for readability, how result-producing functions ( Int and other types) differ from action functions with Unit, and from “non-returning” functions with Nothing. At the end— a mini app and typical mistakes.

In this lecture, we’ll break down how, in Kotlin, you can simplify function calls using default values and named arguments: how to make parameters optional, how to use defaults that depend on other parameters, why parameter order matters, how to safely mix positional and named arguments, and how to apply this in the mini-project “Wallet”. At the end—common mistakes and practical criteria for choosing between defaults and naming.

In this lecture, we look at two Kotlin tools that help keep code compact and readable: a short function body (expression body) via = and local functions (nested fun). We will cover type inference, cases where it is better to keep a block body, and also build a mini app — an “expense jar” — with input, parsing, and validation, including a process diagram in mermaid.

In this lecture, we break down two different ordering mechanisms in Kotlin: visibility modifiers public/private (who can use a declaration) and scope — where a name exists in the code at all. With examples, we will see why variables “die” after }, how if/for/while blocks work, why it makes sense to hide helper functions like readInt() and printMenu() as private, what shadowing is, and how to neatly organize a single-file BudgetBuddy project.

In this lecture, you’ll learn how modern IT products are actually built: why development is constant change, how the release process works, why only code running in production creates value, and what stages your code goes through from writing it to delivering benefit to users. With examples, analogies, and real stories from the industry.