Functions and Parameters

Return Values

Use a returned boolean to choose the next value.

return A return value lets the caller keep working with a function's answer.

Return Values

score
ReturnValues.kt
Replay: real traced execution (multi-file project)
fun isPassing(score: Int): Boolean {
    return score >= 70
}

fun main() {
    val score = 68
    val passed = isPassing(score)
    val label = if (passed) "pass" else "retry"

    println("score=$score")
    println("label=$label")
}

fun isPassing(score: Int): Boolean {
    return score >= 70
}

fun main() {
    val score = 70
    val passed = isPassing(score)
    val label = if (passed) "pass" else "retry"

    println("score=$score")
    println("label=$label")
}

fun isPassing(score: Int): Boolean {
    return score >= 70
}

fun main() {
    val score = 95
    val passed = isPassing(score)
    val label = if (passed) "pass" else "retry"

    println("score=$score")
    println("label=$label")
}

  1. score ← 68

    5fun main() {6    val score→ 68 = 68 //@score=70, 957    val passed = isPassing(score68)8    val label = if (passed) "pass" else "retry"

  2. fun isPassing(score: Int): Boolean

    1fun isPassing(score68: Int): Boolean {2    return score68 >= 703}

  3. passed ← false, label ← retry

    6    val score = 68 //@score=70, 957    val passed→ false = isPassing(score68)8    val label→ retry = if (passedfalse) "pass" else "retry"910    println("score=$score68")11    println("label=$labelretry")12}
    outputscore=68
label=retry

  1. score ← 70

    5fun main() {6    val score→ 70 = 707    val passed = isPassing(score70)8    val label = if (passed) "pass" else "retry"

  2. fun isPassing(score: Int): Boolean

    1fun isPassing(score70: Int): Boolean {2    return score70 >= 703}

  3. passed ← true, label ← pass

    6    val score = 707    val passed→ true = isPassing(score70)8    val label→ pass = if (passedtrue) "pass" else "retry"910    println("score=$score70")11    println("label=$labelpass")12}
    outputscore=70
label=pass

  1. score ← 95

    5fun main() {6    val score→ 95 = 957    val passed = isPassing(score95)8    val label = if (passed) "pass" else "retry"

  2. fun isPassing(score: Int): Boolean

    1fun isPassing(score95: Int): Boolean {2    return score95 >= 703}

  3. passed ← true, label ← pass

    6    val score = 957    val passed→ true = isPassing(score95)8    val label→ pass = if (passedtrue) "pass" else "retry"910    println("score=$score95")11    println("label=$labelpass")12}
    outputscore=95
label=pass