1e99510ebc
* Create control_flow.md * Rename control_flow.md to controlflow.md * Added control flow * Added classes * fix: corrected indentation * fix: corrected indentation
90 lines
1.7 KiB
Markdown
90 lines
1.7 KiB
Markdown
---
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title: Control Flow
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---
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# Control Flow
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### Basic Usage
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#### If Expression
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`if` can be used in same way as in other programming languages
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```kotlin
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var min: Int
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if (a < b) {
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min = a
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} else {
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min = b
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}
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```
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`else` can also be omitted if not needed
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```kotlin
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if (a < b) {
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print("a is smaller")
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}
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```
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#### When Expression
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`when` keyword is replacing usual `switch-case` expression
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The else branch is evaluated if none of the other branch conditions are satisfied
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It has powerfull matching branches which support complex evaluations of input argument
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```kotlin
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when (obj) {
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1 -> "One"
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1, 2 -> "One or Two"
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"Hello" -> "Greeting"
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is Long -> "Long"
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!is String -> "Not a string"
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else -> "Unknown"
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}
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```
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Range evaluation
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```kotlin
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when (x) {
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in 1..100 -> print("x is in the range")
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in validNumbers -> print("x is valid")
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!in 10..200 -> print("x is outside the range")
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else -> print("none of the above")
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}
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```
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#### For Loops
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`for` loop can iterate through anything that provides and interator, using `in` operator
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```kotlin
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val fruits = listOf("apple", "banana", "kiwi")
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for (fruit in fruits) {
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println(fruit)
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}
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```
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Iterating through range of numbers
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```kotlin
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for (i in 1..5) {
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println(i)
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}
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```
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#### While Loops
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`while` and `do..while` are used like in most programming languages
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```kotlin
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while (a > 0) {
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a--
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}
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do {
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val b = provideData()
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} while (b != null)
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```
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#### Break and continue keywords
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Used like in most other programming languages
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#### Resources
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* [Basic Syntax Reference](https://kotlinlang.org/docs/reference/basic-syntax.html)
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* [Kotlin Control Flow Reference](https://kotlinlang.org/docs/reference/control-flow.html)
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