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for-loopkotlinreverse

How to make reversed for loop with array index as a start/end point in Kotlin?

now i'm trying to make reversed for a loop.The simple way of reverse for is for(i in start downTo end)

but,what if I use array as a start/end point?

Solution

  • You can loop from the last index calculated by taking size - 1 to 0 like so:

    for (i in array.size - 1 downTo 0) {
    println(array[i])
}

    Even simpler, using the lastIndex extension property:

    for (i in array.lastIndex downTo 0) {
    println(array[i])
}

    Or you could take the indices range and reverse it:

    for (i in array.indices.reversed()) {
    println(array[i])
}