How to simplify this kotlin code if it needs both boolean and nullable checking?

Question

A dataConfig object has a nullable Boolean field urlIsabled, and would like to return based on whether the dataConfig.urlIsabled == null or the negative of the the dataConfig.urlIsabled

val result = if (dataConfig.urlIsabled != null) (dataConfig.urlIsabled != true) else true)

could it be simplified?

See also this question: https://stackoverflow.com/q/32830904 — Ilya, Mar 12 '19 at 20:01

score 4 · Accepted Answer · answered Mar 12 '19 at 20:00

Plot a simple truth table:

| dataConfig.urlIsabled | result |
|-----------------------|--------|
|        null           |  true  |
|        true           |  false |
|        false          |  true  |
|-----------------------|--------|

So the result is true in all cases except when urlIsabled equals true. Thus it can be expressed as:

val result = dataConfig.urlIsabled != true

score 1 · Answer 2 · answered Mar 12 '19 at 19:57

1

You try to return true if dataConfig.urlIsDisabled is null or false.

Just invert the logic and return false if value is equal to true:

val result = !(dataConfig.urlIsabled == true)

answered Mar 12 '19 at 19:57

Pawel

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score 0 · Answer 3 · answered Mar 12 '19 at 19:53

0

Can be simplified as:

val result = dataConfig.urlIsabled in listOf(false, null)

answered Mar 12 '19 at 19:53

Boken

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How to simplify this kotlin code if it needs both boolean and nullable checking?

3 Answers3