Kotlin Exercises
1. Write a program in Kotlin to print prime numbers between 1 and 100.
Soultion
fun main(args : Array<String>) {
var initial = 1
val final = 100
while (initial < final) {
if (printPrimeNumber(initial))
print(initial.toString() + " ")
++initial
}
}
fun printPrimeNumber(num: Int): Boolean {
var flag = true
for (i in 2..num / 2) {
if (num % i == 0) {
flag = false
break
}
}
return flag
}
Output
1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
2. Write a program to print numbers from 10 to 1 using recursion function.
Soultion
fun main(args : Array<String>) {
for (x in 10 downTo 1)
println("$x")
}
Output
10
9
8
7
6
5
4
3
2
1
3. Write a program to differentiate between val and var.
Soultion
fun main(args : Array<String>) {
var x: String = "Tiger"
x = "Lion" //valid
val y: String = "Cow"
y = "Dog" // error
println("$x and $y")
}
Output
Error:(5, 5) Kotlin: Val cannot be reassigned
4. Write a program in kotlin to map the following -
Item 1, Item 2, Item 3, Item 4
22, 10, 12, 33
Soultion
val map = mapOf(Pair("Item 1", 22), Pair("Item 2", 10), Pair("Item 3", 12), Pair("Item 4", 33))
println(map)
Output
{Item 1=22, Item 2=10, Item 3=12, Item 4=33}
5. Write a program in Kotlin to replace is with was respectively in given string.
He is cryling ver loud.
Soultion
fun main(args : Array<String>) {
var a = "He is cryling very loud."
val s = "${a.replace("is", "was")}"
println(s)
}
Output
He was cryling very loud.
6. Write a program to get length of the given string.
He was cryling very loud.
Soultion
fun main(args : Array<String>) {
val s = "He was cryling very loud."
val str = "$s.length is ${s.length}"
println(str)
}
Output
He was cryling very loud..length is 25
7. How to get average of the given array elements.
doubleArrayOf(2.5, 1.8, 3.4)
Soultion
fun main(args : Array<String>) {
val x = doubleArrayOf(2.5, 1.8, 3.4)
val y = x.average()
println(y)
}
Output
2.5666666666666664
8. Write a program to get length of the given string.
He was cryling very loud.
Soultion
fun main(args : Array<String>) {
val s = "He was cryling very loud."
val str = "$s.length is ${s.length}"
println(str)
}
Output
He was cryling very loud..length is 25
9. How to get average of the given array elements.
doubleArrayOf(2.5, 1.8, 3.4)
Soultion
fun main(args : Array<String>) {
val x = doubleArrayOf(2.5, 1.8, 3.4)
val y = x.average()
println(y)
}
Output
2.5666666666666664
10. Write a program to create an array of size 10 containing.
0
2
4
6
8
10
12
14
16
18
Soultion
fun main(args : Array<String>) {
val x = Array(10) { i -> i * 2 }
for(s in x){
println(s);
}
}
Output
0
2
4
6
8
10
12
14
16
18
11. Write a program in kotlin to print the following statment 10 times.
n. Practice makes a man perfect.
Soultion
fun main(args : Array<String>) {
repeat(10) { i ->
println("${i + 1}. Practice makes a man perfect.")
}
}
Output
1. Practice makes a man perfect.
2. Practice makes a man perfect.
3. Practice makes a man perfect.
4. Practice makes a man perfect.
5. Practice makes a man perfect.
6. Practice makes a man perfect.
7. Practice makes a man perfect.
8. Practice makes a man perfect.
9. Practice makes a man perfect.
10. Practice makes a man perfect.
12. Write a program in kotlin to iterate over the following map.
hashMapOf(1 to "car", 2 to "bike", 3 to "cycle", 4 to "truck")
Soultion
fun main(args : Array<String>) {
var map = hashMapOf(1 to "car", 2 to "bike", 3 to "cycle", 4 to "truck")
for ((key, value) in map) {
println("Map[$key] = $value")
}
}
Output
Map[1] = car
Map[2] = bike
Map[3] = cycle
Map[4] = truck