Conditional Statements and Loop Control in Kotlin | CodeSignal Learn

Conditional Statements and Loop Control in Kotlin | CodeSignal Learn

Topic Overview

Welcome! In this lesson, we're exploring special instructions in the Kotlin language: Conditional Statements, along with the break and continue statements. As we've learned, loops allow us to execute a block of code numerous times. By combining these loops with conditional statements and incorporating the useful break and continue instructions, we achieve more robust and efficient code. Let's dive in!

The 'if' Statement

In Kotlin, the if statement triggers actions in our code based on a specific condition. Consider this straightforward example where the if statement determines which message to print based on the value of temperature : Kotlin fun main() {val temperature = 15 if (temperature > 20) {println("Wear light clothes.") // This message will print if the temperature is over 20.} else {println("Bring a jacket.") // This message will print otherwise.}} We can evaluate multiple conditions using else if . This phrase means, "If the previous condition isn't true, then check this one": Kotlin fun main() {val temperature = 15 if (temperature > 30) {println("It's hot outside!") // This will print if the temperature is over 30.} else if (temperature > 20) {println("The weather is nice.") // This will print if the temperature is between 21 and 30.} else {println("It might be cold outside.") // This will print if the temperature is 20 or below.}}

The 'break' Statement

We use the break statement whenever we want to exit a loop prematurely once a condition is met: Kotlin fun main() {val numbers = listOf(1, 3, 7, 9, 12, 15) for (number in numbers) {if (number % 2 == 0) {println("The first even number is: $number") // This prints the first even number. break // This stops the loop after printing the first even number.} println("Number: $number")}}

The 'continue' Statement

The continue statement bypasses the rest of the loop code for the current iteration only: Kotlin fun main() {for (i in 0 until 6) {if (i == 3) {continue // This skips the print command for '3'.} println(i) // This prints the numbers from 0 to 5 except 3.}}

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Use-case with a For Loop

By utilizing the tools we've covered so far, we can craft more flexible loops. Here's a snippet where we terminate the loop once we find "Charlie": fun main() {val names = listOf("Alice", "Bob", "Charlie", "David") for (name in names) {if (name == "Charlie") {println("Found Charlie!") // This prints when 'Charlie' is found. break // This stops the loop after finding 'Charlie'.}}}

Kotlin

fun main() {
    val names = listOf("Alice", "Bob", "Charlie", "David")

    for (name in names) {
        if (name == "Charlie") {
            println("Found Charlie!") // This prints when 'Charlie' is found.
            break // This stops the loop after finding 'Charlie'.
        }
    }
}