Array/List iteration without extra object allocations

To iterate an array without allocating extra objects you can use one of the following ways.

1. for-loop

    for (e in arr) {
        println(e)
    }

2. forEach extension

    arr.forEach {
        println(it)
    }

3. forEachIndexed extension, if you need to know index of each element

    arr.forEachIndexed { index, e ->
        println("$e at $index")
    }