Kotlin Operators (Lesson 5 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.

Overview about the Lesson

This lesson is part of a series of lessons on Kotlin programming. In this lesson, we will cover the operators in Kotlin. We will start by discussing what operators are and how they work.

We will then explore the different types of operators in Kotlin, including arithmetic operators, comparison operators, and logical operators. Finally, we will look at some examples of how to use operators in Kotlin.

Kotlin Operators (Lesson 5 PDF) – page 2

Kotlin Operators (Lesson 5 PDF) – page 3

The Content Of The Lesson

The content of this lesson is divided into the following sections:

What are operators?
Arithmetic operators
Comparison operators
Logical operators
Examples

Why This Lesson

This lesson is important because operators are an essential part of any programming language. They allow us to perform various operations on data types, which is essential for building complex applications. By understanding the operators in Kotlin, you will be able to write more efficient and effective code.

Kotlin Operators: Examples and Output

This lesson’s PDF introduces arithmetic, comparison and logical operators. Run these examples to see exactly what each operator returns.

Arithmetic operators

Operator	Meaning	Example	Result
+	Addition	`7 + 3`	10
–	Subtraction	`7 - 3`	4
*	Multiplication	`7 * 3`	21
/	Division	`7 / 3`	2 (Int division)
%	Remainder (modulo)	`7 % 3`	1
/ with Double	Decimal division	`7.0 / 3`	2.3333333333333335

The remainder operator is handy for checks such as “is this number even?”: n % 2 == 0.

Assignment and increment operators

fun main() {
    var x = 10
    x += 5    // x = 15
    x -= 3    // x = 12
    x *= 2    // x = 24
    x /= 4    // x = 6
    x %= 4    // x = 2
    x++       // x = 3
    println(x)   // 3
}

Comparison operators

Operator	Meaning	Example	Result
==	Equal (compares values)	`"kotlin" == "kotlin"`	true
!=	Not equal	`5 != 3`	true
> / <	Greater / less than	`5 > 3`	true
>= / <=	Greater / less than or equal	`5 <= 5`	true
===	Same object (reference equality)	`a === b`	depends on the objects

In Kotlin, == compares content (it calls equals()), so you can compare strings safely with ==, unlike Java.

Logical operators

fun main() {
    val age = 22
    val hasTicket = true
    println(age >= 18 && hasTicket)   // true: both conditions
    println(age < 12 || age > 65)     // false: neither condition
    println(!hasTicket)               // false: negation
}

&& and || are short-circuiting: if the left side already decides the answer, the right side is not evaluated.

Operator precedence

Kotlin evaluates * / % before + -, then comparisons, then &&, then ||. So 2 + 3 * 4 is 14. Use parentheses whenever the order is not obvious.

Practice exercise

Check whether a year is a leap year: divisible by 4 and not by 100, or divisible by 400.

fun main() {
    val year = 2028
    val isLeap = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0
    println("$year leap year? $isLeap")   // 2028 leap year? true
}

Frequently Asked Questions

Why does 7 / 2 return 3 in Kotlin?

Both values are Int, so Kotlin performs integer division and drops the remainder. Write 7.0 / 2 or 7 / 2.0 to get 3.5.

What is the difference between == and ===?

== checks whether two values are equal; === checks whether two references point to the very same object in memory.

Continue the course

← Previous: Lesson 4: Data Types | Next: Lesson 6: Set Operations & Grouping →

Conclusion

In conclusion, Kotlin provides a rich set of operators that can be used to perform various operations on data types. In this lesson, we covered the different types of operators in Kotlin, including arithmetic operators, comparison operators, and logical operators. We also looked at some examples of how to use operators in Kotlin. By understanding the operators in Kotlin, you will be able to write more efficient and effective code.