How to Use the Kotlin Compiler

To use the Kotlin Compiler, follow these steps:

  1. Navigate to the Kotlin Compiler webpage.
  2. In the code editor, write your Kotlin code.
  3. Click the "RUN" button to compile and run your code.
  4. The output will be displayed in the console below the code editor.

Taking Inputs

In Kotlin, you can take inputs from the user in various ways. Here are some examples:

String Input

print("Enter a string: ")
val input = readLine()!!
println("You entered: $input")

Number Input

print("Enter a number: ")
val num = readLine()!!.toInt()
println("You entered: $num")

Importing Libraries

Kotlin has a rich set of built-in libraries that can be used in your programs. Here are some examples:

Using the Math Library

val result = Math.sqrt(25.0)
println("Square root of 25 is $result")

Using the List Class

val arr = listOf(1, 2, 3, 4, 5)
println("Array: $arr")

Syntax 101

Kotlin is a statically typed programming language that is fully interoperable with Java. Here's a primer on the major syntax basics of Kotlin:


Variables in Kotlin can be declared using var (mutable) and val (immutable).

val name = "John Doe" // Immutable variable
var age = 25 // Mutable variable

Control Structures

Kotlin includes control structures such as if, else, for, while, and when.

// If-Else
if (age > 18) {
} else {

// For loop
for (i in 0 until 5) {

// When
when (day) {
    "Monday" -> println("Start of the work week")
    "Friday" -> println("End of the work week")
    else -> println("Midweek")


Functions in Kotlin are defined with the fun keyword.

fun greet(name: String) {
    println("Hello, $name")

greet("John Doe") // Calls the function with "John Doe" as the argument

Kotlin Online Test

A Kotlin online test is an effective way to assess an individual's Kotlin programming skills, especially in the context of Android development. These tests typically include a mix of theoretical questions and practical coding challenges. By attempting these tests, candidates can demonstrate their understanding of Kotlin concepts, their problem-solving abilities, and their proficiency in writing efficient code. Kotlin online tests are commonly used in technical interviews, coding bootcamps, and online learning platforms to gauge a learner's understanding and proficiency in Kotlin.