Kotlin Starter Pack

romainbsl

20.2K views

01 About this playground

06 Java interoperability

07 Type inference, checks and smart casts

08 Collections

09 Ranges

10 Operator overloading

Previous: Collections Next: Operator overloading

Ranges

Kotlin provide a way to deal with value ranges, so you might be able to simply create and manipulate ranges effortlessly.

Control if a value belong or not to a range of elements.

1
2
3
4
5
6
7
8
9
10
// { autofold
fun checkRange(i: Int) {
//}
if (i in 1..10) { // equivalent of 1 <= i && i <= 10
    println("$i belongs to the range 1..10")
}
// { autofold
}
fun main(args: Array<String>) {
  checkRange(1)
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Iteration over ranges

1
2
3
4
5
6
7
// { autofold
fun main(args: Array<String>) {
//}
for (i in 1..5) println("square($i) gives ${i * i}")
// { autofold
}
//}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Reverse iteration over ranges

1
2
3
4
5
6
7
// { autofold
fun main(args: Array<String>) {
//}
for (i in 5 downTo 1) print(i)
// { autofold
}
//}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Iterating over ranges ... step by step

1
2
3
4
5
6
7
8
9
10
// { autofold
fun main(args: Array<String>) {
//}  
for (i in 1..10 step 2) print(i)
// { autofold 
println() 
// }
for (i in 10 downTo 1 step 2) print(i)
// { autofold
}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Range with exclusion

1
2
3
4
5
6
7
// { autofold
fun main(args: Array<String>) {
//}  
for (i in 1 until 5) print(i)
// { autofold
}
//}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX