Kotlin Syntax & Output (Print Text) (Lesson 2 PDF)

Kotlin is a statically typed programming language that runs on the Java Virtual Machine (JVM). It was developed by JetBrains and is now an official language for Android development. Kotlin is designed to be concise, expressive, and safe. It is also interoperable with Java, which means that you can use Kotlin and Java code together in the same project.

Kotlin Syntax & Output (Print Text) (Lesson 2 PDF)

Overview about the Lesson

In this lesson, you will learn about printing text in Kotlin. You will learn how to use the println() and print() functions to output values and print text. You will also learn how to format strings using string templates.

Kotlin Syntax & Output (Print Text) (Lesson 2 PDF) – page 2

Kotlin Syntax & Output (Print Text) (Lesson 2 PDF) – page 3

The Content of the Lesson

The lesson is divided into two parts. In the first part, you will learn how to use the println() and print() functions to output values and print text. You will also learn how to format strings using string templates. In the second part, you will learn how to use the readLine() function to read input from the user.

Why This Lesson

This lesson is designed for programmers who are new to Kotlin and want to learn how to print text and read input from the user. It is also suitable for programmers who are familiar with Java and want to learn Kotlin.

Kotlin Output in Practice: println, print and String Templates

This lesson’s PDF covers Kotlin’s syntax rules and how to print text. Here is a hands-on summary with runnable examples.

println() vs print()

fun main() {
    print("Hello ")
    print("World")
    println()          // just moves to a new line
    println("Line 1")
    println("Line 2")
}

Output:

Hello World
Line 1
Line 2

print() keeps the cursor on the same line; println() adds a line break after the text.

Printing numbers and calculations

fun main() {
    println(42)
    println(3 + 4 * 2)   // 11, multiplication first
    println(10 / 4)      // 2, whole-number division
    println(10.0 / 4)    // 2.5
}

Note that dividing two whole numbers gives a whole number. Use a decimal (10.0) to get a decimal result.

String templates: mixing text and values

fun main() {
    val item = "Laptop"
    val price = 950
    println("The $item costs $price dollars")
    println("Two of them cost ${price * 2}")
}

Use $variable for a simple variable and ${expression} for any calculation or property, such as ${item.length}.

Special characters

Escape	Meaning	Example output
n	New line	Splits text over two lines
t	Tab	Adds horizontal space
“	Double quote	Prints a quote inside a string
\	Backslash	Prints a single
$	Dollar sign	Prints $ instead of starting a template

Multi-line strings

fun main() {
    val menu = """
        1. New game
        2. Load game
        3. Exit
    """.trimIndent()
    println(menu)
}

Triple-quoted strings keep line breaks exactly as typed, and trimIndent() removes the common leading spaces.

Kotlin syntax rules to remember

Every program starts in fun main().
Semicolons are optional; one statement per line is the norm.
Kotlin is case-sensitive: println works, PrintLn does not.
Code blocks use curly braces { }; indentation is for readability only.

Practice exercise

Print a small receipt with an item name, a quantity of 3 and a unit price of 12.5, and calculate the total with a string template.

fun main() {
    val item = "Notebook"
    val qty = 3
    val unitPrice = 12.5
    println("Item: $item")
    println("Total: ${qty * unitPrice}")   // Total: 37.5
}

Frequently Asked Questions

How do I print a dollar sign in Kotlin?

Escape it with a backslash: println("Price: $5"). A $ not followed by a valid identifier also prints as is.

Can I format numbers to two decimal places?

Yes: println("%.2f".format(37.456)) prints 37.46.

Continue the course

← Previous: Lesson 1: Getting Started | Next: Lesson 3: Comments & Variables →

Conclusion

Printing text and reading input are essential skills for any programmer. In this lesson, you learned how to use the println() and print() functions to output values and print text. You also learned how to format strings using string templates and how to read input from the user using the readLine() function.