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How to check if an array is sorted in Kotlin

How to check if an array is sorted in Kotlin.

Here's a step-by-step tutorial on how to check if an array is sorted in Kotlin:

Step 1: Declare an array​

To start, declare an array of any type. For example, let's create an array of integers:

val numbers = arrayOf(5, 10, 15, 20, 25)

Step 2: Create a function to check if the array is sorted​

Next, create a function that takes an array as a parameter and checks if it is sorted. You can name the function isSorted:

fun isSorted(array: Array<Int>): Boolean {
    // implementation goes here
}

Step 3: Compare adjacent elements​

Inside the isSorted function, iterate over the elements of the array using a for loop. Compare each element with its adjacent element to check if they are in the correct order:

fun isSorted(array: Array<Int>): Boolean {
    for (i in 0 until array.size - 1) {
        if (array[i] > array[i + 1]) {
            return false
        }
    }
    return true
}

Step 4: Test the function​

Now, you can test the isSorted function by passing different arrays to it. Here's an example:

fun main() {
    val numbers = arrayOf(5, 10, 15, 20, 25)
    val isNumbersSorted = isSorted(numbers)
    println("Is numbers sorted? $isNumbersSorted") // Output: Is numbers sorted? true

    val letters = arrayOf("a", "b", "c", "z", "y")
    val isLettersSorted = isSorted(letters)
    println("Is letters sorted? $isLettersSorted") // Output: Is letters sorted? false
}

Step 5: Handle arrays with a custom sorting order​

If you want to check if an array is sorted based on a custom sorting order, you can modify the comparison logic inside the isSorted function. For example, let's check if an array of strings is sorted in descending order:

fun isSortedDescending(array: Array<String>): Boolean {
    for (i in 0 until array.size - 1) {
        if (array[i] < array[i + 1]) {
            return false
        }
    }
    return true
}

Now you can test the isSortedDescending function with a different array:

fun main() {
    val numbers = arrayOf("z", "y", "x", "a")
    val isDescending = isSortedDescending(numbers)
    println("Is numbers sorted in descending order? $isDescending") // Output: Is numbers sorted in descending order? true
}

That's it! You now know how to check if an array is sorted in Kotlin.