Kotlin Operators

Operators are used to perform operations on variables and values.

The value is called an operand, while the operation (to be performed between the two operands) is defined by an operator:

Operand	Operator	Operand
100	+	50

In the example below, the numbers 100 and 50 are operands, and the + sign is an operator:

Example

var x = 100 + 50

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Although the + operator is often used to add together two values, like in the example above, it can also be used to add together a variable and a value, or a variable and a variable:

Example

var sum1 = 100 + 50       // 150 (100 + 50)
var sum2 = sum1 + 250     // 400 (150 + 250)
var sum3 = sum2 + sum2    // 800 (400 + 400)

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Kotlin divides the operators into the following groups:

Arithmetic operators
Assignment operators
Comparison operators
Logical operators

Arithmetic Operators

Arithmetic operators are used to perform common mathematical operations.

Operator	Name	Description	Example	Try it
+	Addition	Adds together two values	x + y	Try it »
-	Subtraction	Subtracts one value from another	x - y	Try it »
*	Multiplication	Multiplies two values	x * y	Try it »
/	Division	Divides one value from another	x / y	Try it »
%	Modulus	Returns the division remainder	x % y	Try it »
++	Increment	Increases the value by 1	++x	Try it »
--	Decrement	Decreases the value by 1	--x	Try it »

Kotlin Assignment Operators

Assignment operators are used to assign values to variables.

In the example below, we use the assignment operator (=) to assign the value 10 to a variable called x:

Example

var x = 10

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The addition assignment operator (+=) adds a value to a variable:

Example

var x = 10
x += 5

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A list of all assignment operators:

Operator	Example	Same As	Try it
=	x = 5	x = 5	Try it »
+=	x += 3	x = x + 3	Try it »
-=	x -= 3	x = x - 3	Try it »
*=	x *= 3	x = x * 3	Try it »
/=	x /= 3	x = x / 3	Try it »
%=	x %= 3	x = x % 3	Try it »

Kotlin Comparison Operators

Comparison operators are used to compare two values, and returns a Boolean value: either true or false.

Operator	Name	Example	Try it
==	Equal to	x == y	Try it »
!=	Not equal	x != y	Try it »
>	Greater than	x > y	Try it »
<	Less than	x < y	Try it »
>=	Greater than or equal to	x >= y	Try it »
<=	Less than or equal to	x <= y	Try it »

You will learn much more about Booleans in the Boolean chapter and Conditions.

Kotlin Logical Operators

Logical operators are used to determine the logic between variables or values:

Operator	Name	Description	Example	Try it
&&	Logical and	Returns true if both statements are true	x < 5 && x < 10	Try it »
\|\|	Logical or	Returns true if one of the statements is true	x < 5 \|\| x < 4	Try it »
!	Logical not	Reverse the result, returns false if the result is true		Try it »