150: Learning Kotlin – Returns, Jumps & Labels

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Code

data class Customer(val isPlatinum: Boolean)

fun main() {

    val customer = Customer(false)

    println("Number of points customer has: ${calculatePoints(customer)}")

    // Break out of the loop once we're over 25
    for (i in 1..100) {
        if (i > 25) {
            break
        } else {
            println(i)
        }
    }


    // Skip all even numbers
    for (i in 1..100) {
        if (i % 2 == 0) {
            continue
        } else {
            println(i)
        }
    }


    // Break out of the outer loop (which breaks out of the inner too) using a label
    [email protected] for (i in 1..100) {
        for (j in 100..200) {
            if (j > 150) [email protected] // This will break out of the inner loop and outer loop
            else println("i: $i, j: $j")
        }
    }

    // Continue processing the next outer loop value when a condition is met.
    [email protected] for (i in 1..100) {
        for (j in 100..200) {
            if (j > 150) [email protected] // This will break out of the inner loop and outer loop
            else println("i: $i, j: $j")
        }
    }

    // returns with label
    example1()
    example2()

    println("I'm done processing!")
}

fun calculatePoints(customer: Customer): Int {
    if (customer.isPlatinum) {
        return 100000
    } else {
        return 10
    }
}


fun example1() {
    listOf(1, 2, 3, 4, 5, 6, 7, 8, 9).forEach {
        if (it > 7) {
            return
        } else {
            println(it)
        }
    }
    println("This wont print :( because return exited the bar() function")
}

fun example2() {
    listOf(1, 2, 3, 4, 5, 6, 7, 8, 9).forEach [email protected] {
        if (it > 7) {
            [email protected]
        } else {
            println(it)
        }
    }
    println("This will print! :) return exited the forEach!")
}

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149: Learning Kotlin: inline classes and Type driven design

In this quick fragment, Kaushik talks about the new Kotlin 1.3 experimental feature “inline classes” and how it helps with Type driven design.

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Type driven design resources

Kotlin KEEP

vs typealias

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138: Decompress – kotlin scripting

In this mini fragment, Donn asks KG about a recent hackathon side project that he worked on with Kotlin scripting.

We go into kotlin scripting (using kscript), pros cons, setting it up and more. We’ve added links some interesting resources, so you want to make sure you check out the shownotes for this one, so you too can explore kotlin scripting and see if it’s a fit for you.

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Existing solutions for poll/vote tabulation

Misc


// slick kotlin usage override fun onCreate(savedInstanceState: Bundle?) = super.onCreate(savedInstanceState).also { setContentView(R.layout.activity_something) // ... }

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136: Kotlin Extension Functions

In this fragment episode, Donn talks about Kotlin extension functions. He discusses what they are, how to build them, why they’re useful, how to organize them, visibility and how to call them Java and much more.

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Show Notes

`

import android.view.View

fun View.gone() {
    this.visibility = View.GONE
}

fun View.visible() {
    this.visibility = View.VISIBLE
}

`

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122: Learning Kotlin – typealias

In this episode of learning kotlin, we look at the typealias keyword. The typealias keyword allows you to provide alternate names for existing types and and function types. Learn how, why and when you can use it in this episode

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