Better way to set all the keys to map to false in a mutable map

Question

I have a mutable map

val weeklyCheck = mutableMapOf(
    Day.MONDAY to true,
    Day.TUESDAY to true,
    Day.WEDNESDAY to true,
    Day.THURSDAY to true,
    Day.FRIDAY to true,
    Day.SATURDAY to true,
    Day.SUNDAY to true
)

How do I set all the keys to false. Currently I am using something like this, is there a better way to do this.

private fun resetDays() {
    weeklyCheck.put(Days.MONDAY, false)
    weeklyCheck.put(Days.TUESDAY, false)
    weeklyCheck.put(Days.WEDNESDAY, false)
    weeklyCheck.put(Days.THURDSAY, false)
    weeklyCheck.put(Days.FRIDAY, false)
    weeklyCheck.put(Days.SATURDAY, false)
    weeklyCheck.put(Days.SUNDAY, false)
}

I'd find this question clearer if it asked about setting all the _values_ to false — or, equivalently, about setting all the keys to _map_ to false. — gidds, Jun 08 '21 at 08:39

score 7 · Accepted Answer · answered Jun 08 '21 at 07:29

7

You can use replaceAll - ignore the given key and value, and just return false no matter what. This will replace everything with false.

weeklyCheck.replaceAll { _, _ -> false }

answered Jun 08 '21 at 07:29

Sweeper

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Is there any way to iterate over all the keys and setting the value to false? – A-run Jun 08 '21 at 08:13
4

That's what `replaceAll` does... @ARUNSINGH – Sweeper Jun 08 '21 at 08:13

score 1 · Answer 2 · answered Jun 08 '21 at 08:06

1

This can be used to achieve same results:

Days.values().forEach { weekFilter[it] = false }

answered Jun 08 '21 at 08:06

A-run

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13

Better way to set all the keys to map to false in a mutable map

2 Answers2