Kotlin for Beginners

Kotlin is a concise, cross-platform language that runs on the JVM and enables server, Android, iOS, desktop, and web development; this course breaks down the basics and gets you started.

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Create a Kotlin project in IntelliJ IDEA by selecting Kotlin as the language, choosing a build system, configuring the JDK, and running a Hello World program to verify setup.

Explore the Kotlin IDE basics. Run Kotlin programs from the main function using the play button, and manage files under src/main/kotlin while using built-in git, terminal, problems, and settings tools.

Explain Kotlin's main function as the entry point and how to use program arguments, compare Kotlin's fun main with Java's main, and print to the console.

Explore Kotlin’s reserved keywords—hard, soft, and modifier keywords—and learn how they cannot be used for anything else than writing Kotlin code, with examples like var, fun, and when.

Create Kotlin files, run main functions, print to the console, and master single-line and multi-line comments that don’t execute.

Explore println and print in Kotlin, including overloading and producing output to the console. See how backslash n creates a new line and how system.out.println is called in Java.

Declare and use variables as placeholders to store single values, print them, and format output with string interpolation in Kotlin, introducing var, val, basic data types, and future data structures.

Kotlin treats most values as objects; declare variables with var and a type after a colon, and learn datatypes like int, long, double, float, boolean, string, and char.

Explore the Kotlin any type, a universal supertype for numbers and strings, and why you should prefer specific types over any. See var declarations and sample type assignments.

Learn type inference in Kotlin to omit explicit types, making variables neater and letting IntelliJ highlight redundant annotations while still knowing when to declare types.

Explore when to use val and var in Kotlin, highlighting immutable vs mutable variables, reassignments, Java final analogy, and the role of immutability in a multithreaded environment.

Discover the Kotlin const keyword, how it differs from val and var, and why constants remain known before execution. Define const outside functions; this mirrors static final in Java.

Explore how Kotlin's null safety eliminates null pointer exceptions by default, using nullable types with a question mark and safe handling of null values, demonstrated with name and brand examples.

Explore the Kotlin string class to store text, create strings with val, print them, access characters by index, and use methods like uppercase, lowercase, length, and isEmpty.

Learn to interpolate strings in Kotlin using string templates, replacing concatenation with concise syntax like name and age, and use $name or ${name} for expressions.

Explore Kotlin's multiline strings, see how trim indent preserves indentation and line breaks, and use format specifiers like %s and %d to insert variables such as names into emails.

Learn how to compare strings in kotlin using double equals, triple equals, and dot equals, including contents versus memory location and the role of the string pool.

Explore arithmetic operators in Kotlin, including addition, subtraction, division, multiplication, and modulus. See ten and two illustrate each operation and the formatted output.

Learn how to use Kotlin's math utilities to access pi as a double, compute max, min, square roots, and rounding, and manage imports and packages.

Explore how the plus operator in Kotlin acts as addition for numbers and concatenation for strings, illustrating polymorphism with 10 + 10 and 'ten' + 'ten'.

Explore the Kotlin boolean data type, learn true, false, and nullable booleans, and see how to use if statements with null values in practical examples.

Learn how if statements run code based on conditions, using comparison, booleans, and logical operators including and or. Understand else blocks and code outside the if.

Kotlin arrays use arrayOf to store multiple values with zero-based indexing and type constraints. Learn to access, modify, check membership with in, and print with contentToString.

Learn how lists differ from arrays by becoming expandable, construct lists with listOf and emptyList, and use read-only lists to access size, first, last, contains, and indexOf.

Loop through lists and arrays in Kotlin using the for construct, accessing elements, handling indexes, and performing actions like capitalizing first letters and printing results.

Learn how functions power Kotlin programs, from declaring and invoking a function to using built-in functions like println and string transforms such as uppercase and lowercase.

Define and invoke Kotlin functions using fun, including a greet example outside main, return type unit, and default public access, with parameters.