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How to check if an array is a subset of another array in Kotlin

How to check if an array is a subset of another array in Kotlin.

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

Step 1: Create two arrays​

Start by creating two arrays: the main array and the sub-array. The main array is the array in which you want to check if the sub-array is a subset of it.

val mainArray = arrayOf(1, 2, 3, 4, 5)
val subArray = arrayOf(2, 3)

Step 2: Check if the sub-array is a subset of the main array​

To check if the sub-array is a subset of the main array, you can use the containsAll() function. This function returns true if the main array contains all the elements of the sub-array.

val isSubset = mainArray.containsAll(subArray)

Step 3: Print the result​

Finally, you can print the result to see if the sub-array is a subset of the main array.

if (isSubset) {
    println("The sub-array is a subset of the main array")
} else {
    println("The sub-array is not a subset of the main array")
}

Step 4: Complete example​

Here's the complete example code:

fun main() {
    val mainArray = arrayOf(1, 2, 3, 4, 5)
    val subArray = arrayOf(2, 3)
    
    val isSubset = mainArray.containsAll(subArray)
    
    if (isSubset) {
        println("The sub-array is a subset of the main array")
    } else {
        println("The sub-array is not a subset of the main array")
    }
}

This will output:

The sub-array is a subset of the main array

Step 5: Handle duplicates and order​

By default, the containsAll() function checks if the main array contains all the elements of the sub-array, regardless of their order and duplicates. However, if you want to consider the order and duplicates as well, you can use the contentEquals() function.

val isSubset = mainArray.contentEquals(subArray)

This function returns true if both arrays have the same elements in the same order, including duplicates.

That's it! You now know how to check if an array is a subset of another array in Kotlin.