Careeroza

Basic Syntax

Program Structure

Example

A Kotlin file can contain functions directly. fun declares a function, curly braces hold its body, and each statement usually sits on its own line.

fun main() {
    println("Line one")
    println("Line two"); println("Two statements on one line need a semicolon")
}

Output

Line one
Line two
Two statements on one line need a semicolon

Syntax Rules

  • fun main() is the entry point.
  • Kotlin is case-sensitive: println works, PrintLn does not.
  • Semicolons are optional at the end of a line.
  • Blocks use { }; indentation is for readability only (4 spaces is the convention).
  • Strings use double quotes "text"; a single character uses single quotes 'A'.
  • File names end with .kt (scripts use .kts).

Packages and Imports

Real projects put each file in a package and import what they need. Many common functions (println, listOf, maxOf) are imported automatically.

Example

Here we import sqrt and PI from the kotlin.math package.

import kotlin.math.PI
import kotlin.math.sqrt

fun main() {
    println(sqrt(144.0))
    println(PI)
}

Output

12.0
3.141592653589793