# Instruction

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Kotlin offers seven types of operators. They are:

• Arithmetic operators
• Assignment operators
• Unary operators
• Logical operators
• Relational operators
• Special operators

## Using Arithmetic Operators

Arithmetic operators allow you to perform mathematical operations on values.

``````val add = 9+1

val subtract = 100 - 50
println(subtract) // prints 50

val multiply = 6 * 3
println(multiply) // prints 18

val divide = 10 / 2
println(divide) // prints 5

val remainder = 11 % 2
println(remainder) // prints 1
``````

## Using Assignment Operators

Assignment operators let you assign values to variables. = is the simplest assignment operator that allows you to assign a value, as shown below:

``````val a = 5
``````
``````var a = 5
a += 2 // equivalent to a = a + 2
println(a) // prints 7

var b = 10
b /= 2 // equivalent to b = b / 2
println(b) // prints 5
``````

## Using Unary Operators

Unary operators perform operations on a single operand. Kotlin offers two unary operators:

``````var a = 3
a++ // equivalent to a = a + 1
println(a) // prints 4

var b = 10
b-- //equivalent to b = b -1
println(b) // prints 9
``````

## Using Logical Operators

Logical operators allow you to perform logical operations. These operations have a Boolean result, true or false. Kotlin offers three logical operators:

``````
// Logical AND (&&)
val number = 20
val isEvenMultipleOfFive = number % 2 == 0 && number % 5 == 0
println("\$number is both even and a multiple of 5: \$isEvenMultipleOfFive") //prints true

//Logical OR (||)
val raining = true
val temperature = 35

val carryUmbrella = raining || temperature > 30
println("Carry an umbrella: \$carryUmbrella") // prints true

//Logical NOT
val isTrue = true
println(!isTrue) // prints false
``````

## Using Relational Operators

Relational operators allow you to compare two values, giving you a Boolean result. The relational operators offered by Kotlin are:

``````var a = 5
var b = 5
println(a == b) // prints true

a = 9
b = 10
println(a != b) // prints true
println(a < b) // prints true
println(a > b) // prints false

a = 25
println (a >= 25) // prints true
println (a <= 25) // prints true
``````

## Using Special Operators

In addition to the operators mentioned earlier, Kotlin offers two special operators:

``````var nullableMessage: String? = null
val result = nullableMessage ?: "variable is null"
println(result) // prints "variable is null"

val length = nullableMessage?.length
println(length) //prints null
``````