val immutableList = listOf(1, 2, 3)
val immutableSet = setOf("a", "b", "c")
val immutableMap = mapOf("key1" to "value1", "key2" to "value2")
fun List<Int>.sum(): Int {
var result = 0
for (item in this) {
result += item
}
return result
}
val list = listOf(1, 2, 3)
val sum = list.sum()
val list = listOf(1, 2, 3, 4, 5)
val evenNumbers = list.filter { it % 2 == 0 }
val doubledNumbers = list.map { it * 2 }
val sum = list.reduce { acc, i -> acc + i }
val str = "Hello, World!"
val parts = str.split(",")
val upperCase = str.toUpperCase()
val str = "Hello, World!"
val replacedStr = str.replace(Regex("[aeiou]"), "*")
val file = File("path/to/file.txt")
val lines = file.readLines()
file.writeText("Hello, World!")
