Operators are the special symbols that perform different operation on operands. For example + and – are operators that perform addition and subtraction respectively. Like Java, Kotlin contains different kinds of operators.
- Arithmetic operator
- Relation operator
- Assignment operator
- Unary operator
- Logical operator
- Bitwise operator
Arithmetic Operators –
| Operators |
Meaning |
Expression |
Translate to |
| + |
Addition |
a + b |
a.plus(b) |
| – |
Subtraction |
a – b |
a.minus(b) |
| * |
Multiplication |
a * b |
a.times(b) |
| / |
Division |
a / b |
a.div(b) |
| % |
Modulus |
a % b |
a.rem(b) |
Kotlin
fun main(args: Array<String>)
{
var a = 20 var b = 4 println("a + b = " + (a + b))
println("a - b = " + (a - b))
println("a * b = " + (a.times(b)))
println("a / b = " + (a / b))
println("a % b = " + (a.rem(b)))
}
|
Output:
a + b = 24
a - b = 16
a * b = 80
a / b = 5
a % b = 0
Relational Operators –
| Operators |
Meaning |
Expression |
Translate to |
| > |
greater than |
a > b |
a.compareTo(b) > 0 |
| < |
less than |
a < b |
a.compareTo(b) < 0 |
| >= |
greater than or equal to |
a >= b |
a.compareTo(b) >= 0 |
| <= |
less than or equal to |
a <= b |
a.compareTo(b) <= 0 |
| == |
is equal to |
a == b |
a?.equals(b) ?: (b === null) |
| != |
not equal to |
a != b |
!(a?.equals(b) ?: (b === null)) > 0 |
Kotlin
fun main(args: Array<String>)
{
var c = 30
var d = 40
println("c > d = "+(c>d))
println("c < d = "+(c.compareTo(d) < 0))
println("c >= d = "+(c>=d))
println("c <= d = "+(c.compareTo(d) <= 0))
println("c == d = "+(c==d))
println("c != d = "+(!(c?.equals(d) ?: (d === null))))
}
|
Output:
c > d = false
c < d = true
c >= d = false
c <= d = true
c == d = false
c != d = true
Assignment Operators –
| Operators |
Expression |
Translate to |
| += |
a = a + b |
a.plusAssign(b) > 0 |
| -= |
a = a – b |
a.minusAssign(b) < 0 |
| *= |
a = a * b |
a.timesAssign(b)>= 0 |
| /= |
a = a / b |
a.divAssign(b) <= 0 |
| %= |
a = a % b |
a.remAssign(b) |
Kotlin
fun main(args : Array<String>){
var a = 10
var b = 5
a+=b
println(a)
a-=b
println(a)
a*=b
println(a)
a/=b
println(a)
a%=b
println(a)
}
|
Output:
15
10
50
10
0
Unary Operators –
| Operators |
Expression |
Translate to |
| ++ |
++a or a++ |
a.inc() |
| — |
–a or a– |
a.dec() |
Kotlin
fun main(args : Array<String>){
var e=10
var flag = true
println("First print then increment: "+ e++)
println("First increment then print: "+ ++e)
println("First print then decrement: "+ e--)
println("First decrement then print: "+ --e)
}
|
Output:
First print then increment: 10
First increment then print: 12
First print then decrement: 12
First decrement then print: 10
Logical Operators –
| Operators |
Meaning |
Expression |
| && |
return true if all expressions are true |
(a>b) && (a>c) |
| || |
return true if any of expression is true |
(a>b) || (a>c) |
| ! |
return complement of the expression |
a.not() |
Kotlin
fun main(args : Array<String>){
var x = 100
var y = 25
var z = 10
var result = false
if(x > y && x > z)
println(x)
if(x < y || x > z)
println(y)
if( result.not())
println("Logical operators")
}
|
Output:
100
25
Logical operators
Bitwise Operators –
| Operators |
Meaning |
Expression |
| shl |
signed shift left |
a.shl(b) |
| shr |
signed shift right |
a.shr(b) |
| ushr |
unsigned shift right |
a.ushr() |
| and |
bitwise and |
a.and(b) |
| or |
bitwise or |
a.or() |
| xor |
bitwise xor |
a.xor() |
| inv |
bitwise inverse |
a.inv() |
Kotlin
fun main(args: Array<String>)
{
println("5 signed shift left by 1 bit: " + 5.shl(1))
println("10 signed shift right by 2 bits: : " + 10.shr(2))
println("12 unsigned shift right by 2 bits: " + 12.ushr(2))
println("36 bitwise and 22: " + 36.and(22))
println("36 bitwise or 22: " + 36.or(22))
println("36 bitwise xor 22: " + 36.xor(22))
println("14 bitwise inverse is: " + 14.inv())
}
|
Output:
5 signed shift left by 1 bit: 10
10 signed shift right by 2 bits: : 2
12 unsigned shift right by 2 bits: 3
36 bitwise and 22: 4
36 bitwise or 22: 54
36 bitwise xor 22: 50
14 bitwise inverse is: -15