## Kotlin Tutorial

## Kotlin Classes

## Operators

In Kotlin, we have various operators to perform different operations like arithmetic, assignment, logical, and comparison operators etc.

While performing any operations on values we have **operators **& **operands**. The value on which an operation is performed is **operand**, while the operation to be performed between two operands is called **operator**.

In the example below **10 **and **5 **are operands, while the **+ **between them is operator.

**Example:**

` ````
```var a = 10 + 5
println(a)

The code above outputs:

## Arithmetic Operators

Arithmetic operators are used to perform mathematical operations.

Example of Arithmetic operators:

` ````
```var a = 10
var b = 50
var result = 0
result = a + b
println("a + b = $result")
result = a - b
println("a - b = $result")
result = a * b
println("a * b = $result")
result = a / b
println("a / b = $result")
result = a % b
println("a % b = $result")
result = ++a
println("a increment = $result")
result = --b
println("b decrement = $result")

The code above outputs:

a + b = 60

a – b = -40

a * b = 500

a / b = 0

a % b = 10

a increment = 11

b decrement = 49

## Assignment Operators

Assignment operator is used to assign a value to a variable. We have been using this operator for a long time. That is the “ = “ operator.

In the example below we assign the value **10 **to the variable **a**.

**Example:**

` ````
```var a = 10

Example of Assignment operators.

` ````
```// Assign 10 to variable a
var a = 10
println(a)
// Add 10 - using addition assignment operator
a += 10
println(a)
// Subtract 10 - using subtraction assignment operator
a -= 10
println(a)
// And so on

The code above outputs:

10

20

10

## Comparison Operators

Comparison operators are used to compare two values and result in true or false which means a Boolean value.

Example of comparison operators.

` ````
```var a = 10
var b = 20
// a is equal to b ( == )
println(a == b)
// a is greater than b ( > )
println(a > b)
// a is less than b ( < )
println(a < b)
// a is not equal to b ( != )
println(a != b)
// and so on

The code above outputs:

false

false

true

true

You will learn more about conditional statements in later chapters

## Logical Operators

In Kotlin, There are 3 logical operators. And are used in conditional statements (if, else).

They are:

## AND ( && ) Logical operator.

In logical operator AND or && (1 and 1 = true) means both conditions must be true in case the result will be true otherwise the result will be false.

AND operator Example:

` ````
```var a = 10
var b = 20
// Here both conditions are false; so result will be false
println(a == b && a > b)
// Here one condition is false; so result will be false
println(a == b && a != b)
// Here both conditions are true; so result will be true
println(a < b && a != b)

The code above outputs:

false

false

true

## OR ( || ) Logical operator.

In logical operator OR or ( || ), If both conditions are false in case the result will be false otherwise the result will be true.

OR operator Example:

` ````
```var a = 10
var b = 20
// Here both conditions are false; so result will be false
println(a == b || a > b)
// Here one condition is false; so result will be true
println(a == b || a != b)
// Here both conditions are true; so result will be true
println(a < b || a != b)

The code above outputs:

false

true

true

## NOT ( ! ) Logical operator.

The NOT operator is pretty much simple. It reverses the result; like if the result is true this will make it false or if it is false this will make it true.

**NOT operator Example:**

` ````
```var a = 20
var b = 20
// The condition below is true
println(a == b)
// Let's make it false by putting NOT (!) operator
println(a !== b)

The code above outputs:

true

false