Kotlin Operators

Operators are used to performing operations on variables and values.

They are various kinds of operators available in Kotlin.

• Arithmetic operator
• Relation operator
• Assignment operator
• Unary operator
• Bitwise operation
• Logical operator

Arithmetic Operator

Arithmetic operators are used to perform basic mathematical operations such as addition (+), subtraction (-), multiplication (*), division (/), etc.

Operator	Description	Expression	Translate to
+	Addition	a+b	a.plus(b)
-	Subtraction	a-b	a.minus(b)
*	Multiply	a*b	a.times(b)
/	Division	a/b	a.div(b)
%	Modulus	a%b	a.rem(b)

Relation Operator

The relation operator shows the relation and compares between operands. Following are the different relational operators:

Operator	Description	Expression	Translate to
>	greater than	a>b	a.compateTo(b)>0
<	Less than	a<b	a.compateTo(b)<0
>=	greater than or equal to	a>=b	a.compateTo(b)>=0
<=	less than or equal to	a<=b	a?.equals(b)?:(b===null)
==	is equal to	a==b	a?.equals(b)?:(b===null)
!=	not equal to	a!=b	!(a?.equals(b)?:(b===null))

Assignment operator

Assignment operator "=" is used to assign a value to another variable. The assignment of value takes from right to left.

Operator	Description	Expression	Convert to
+=	add and assign	a+=b	a.plusAssign(b)
-=	subtract and assign	a-=b	a.minusAssign(b)
*=	multiply and assign	a*=b	a.timesAssign(b)
/=	divide and assign	a/=b	a.divAssign(b)
%=	mod and assign	a%=b	a.remAssign(b)

Unary Operator

A unary operator is used with only a single operand. Following are some unary operators given below.

Operator	Description	Expression	Convert to
+	unary plus	+a	a.unaryPlus()
-	unary minus	-a	a.unaryMinus()
++	increment by 1	++a	a.inc()
--	decrement by 1	--a	a.dec()
!	not	!a	a.not()

Logical Operator

Logical operators are used to checking conditions between operands. A list of logical operators is given below.

Operator	Description	Expression	Convert to
&&	return true if all expression are true	(a>b) && (a>c)	(a>b) and (a>c)
||	return true if any expression are true	(a>b) || (a>c)	(a>b) or(a>c)
!	return complement of expression	!a	a.not()

Bitwise Operation

In Kotlin, there is not any special bitwise operator. Bitwise operation is done using the named function.

Named Function	Description	Expression
shl (bits)	signed shift left	a.shl(b)
shr (bits)	signed shift right	a.shr(b)
ushr (bits)	unsigned shift right	a.ushr(b)
and (bits)	bitwise and	a.and(b)
or (bits)	bitwise or	a.or(b)
xor (bits)	bitwise xor	a.xor(b)
inv()	bitwise inverse	a.inv()

fun main(){
    //Arithmetic operators (+, -, *, /, %)
    var result = 5+3
    result = result / 2
    // alternatively
    // result /= 2
    result = result * 5
    result = result - 1
    var moduloResult = 5%2
    println( moduloResult)

    //Comparison operators (==, !=, <, >, <=, >=)
    val isEqual = 5==3
    // Concatenation - adding of "Strings"
    println("isEqual is " + isEqual)
    val isNotEqual = 5!=5
    // Kotlin has a feature called String Interpolation.
    // This feature allows you to directly insert a template expression inside a String.
    // Template expressions are tiny pieces of code that are evaluated and
    // their results are concatenated with the original String.
    // A template expression is prefixed with $ symbol.
    // Following are examples of String interpolation
    println("isNotEqual is $isNotEqual")

    println("is5Greater3 ${5 > 3}")
    println("is5LowerEqual3 ${5 >= 3}")
    println("is5LowerEqual5 ${5 >= 5}")

    //Assignment operators (+=, -=, *=, /=, %=)
    var myNum = 5
    myNum += 3
    println("myNum is $myNum")
    myNum *= 4
    println("myNum is $myNum")


    //Increment & Decrement operators (++, --)
    myNum++
    println("myNum is $myNum")
    // increments after use
    println("myNum is ${myNum++}")
    // increments before use
    println("myNum is ${++myNum}")
    println("myNum is ${--myNum}")

}

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