🧐 What are Ranges in Kotlin?
Ranges in Kotlin are a simple and effective way of defining a set of values. They are represented by the .. operator and consist of a start and end value separated by this operator. For example, 1..10 defines a range from 1 to 10 inclusive.
💡 Pro tip: Ranges are often used in for loops to iterate over a sequence of values. They can also be used in conditional statements and other places where you need to define a range of values.
🚀 What are Progressions in Kotlin?
Progressions are a type of range that represent a sequence of values with a constant step. They are defined using the rangeTo() function or the step property. For example, 1..10 step 2 defines a progression with a step of 2 between each value.
💡 Pro tip: Progressions are useful when you need to generate a sequence of values with a consistent pattern, such as every other number.
👨💻 How to use Ranges and Progressions in Kotlin?
Using ranges and progressions in Kotlin is easy. Here are a few examples:
fun main(){
// Define a range
val range = 1..10
// Iterate over the values in the range
for (i in range) {
println(i)
}
// Define a progression
val progression = 1..10 step 2
// Iterate over the values in the progression
for (i in progression) {
println(i)
}
// Check if a value is in a range
val value = 5
if (value in range) {
println("$value is in the range!")
}
}
🎉 Congratulations, you now know the basics of using ranges and progressions in Kotlin! 🎉
🤖 One last thing: Did you know that Kotlin also has a downTo operator? This allows you to define ranges that decrease in value, such as 10 downTo 1. Cool, huh? 😎
As I mentioned earlier, progressions are a type of range that represent a sequence of values with a constant step. They are defined using the rangeTo() function or the step property.
In addition to the basic syntax I showed earlier, there are a few other things you can do with progressions in Kotlin.
👉 Custom Steps
One useful feature of progressions is the ability to specify a custom step value using the step property. This allows you to create progressions with steps other than 1.
For example, here’s how you could create a progression of even numbers from 2 to 10:
fun main(){
val evenProgression = 2..10 step 2
for(value in evenProgression){
println(value)
}
}
This will create a progression that starts at 2, increments by 2, and stops at 10. The resulting progression will be 2, 4, 6, 8, 10.
👉 Reversed Progressions
Another handy feature of progressions is the ability to reverse them using the reversed() function. This returns a new progression with the same values but in reverse order.
For example, here’s how you could create a reversed progression of odd numbers from 9 to 1:
fun main(){
val oddReversedProgression = 9 downTo 1 step 2
for(value in oddReversedProgression){
println(value)
}
}
This will create a progression that starts at 9, decrements by 2, and stops at 1. The resulting progression will be 9, 7, 5, 3, 1.
👉 Converting Progressions to Lists
If you need to work with a progression as a list, you can easily convert it using the toList() function. This returns a list of all the values in the progression.
For example:
fun main(){
val progression = 1..10 step 2
val list = progression.toList()
println(list)
}
This will create a progression of odd numbers from 1 to 9, and then convert it to a list. The resulting list will be [1, 3, 5, 7, 9].
👉 Summing Progressions
If you need to sum the values in a progression, you can use the sum() function. This returns the sum of all the values in the progression.
For example:
fun main(){
val progression = 1..10 step 2
val sum = progression.sum()
}
This will create a progression of odd numbers from 1 to 9, and then calculate the sum of all the values. The resulting sum will be 25.