How to check if an array has duplicate elements in Kotlin

How to check if an array has duplicate elements in Kotlin.

Here's a detailed step-by-step tutorial on how to check if an array has duplicate elements in Kotlin:

Start by defining an array in Kotlin. You can use the arrayOf function to create an array with some elements. For example, let's create an array of integers:
```
val array = arrayOf(1, 2, 3, 4, 4, 5)
```
Next, we will use a set to efficiently check for duplicate elements in the array. Create an empty set using the HashSet class:
```
val set = HashSet<Int>()
```
Now, we will iterate over each element in the array using a loop. For each element, we will check if it already exists in the set. If it does, then it is a duplicate element. If it doesn't, we will add it to the set.
```
for (element in array) {
    if (set.contains(element)) {
        println("Duplicate element found: $element")
    } else {
        set.add(element)
    }
}
```
In this example, if the array contains duplicate elements, it will print the duplicate element with the message "Duplicate element found: ".
Another approach to check for duplicate elements is by using the distinct function. This function returns a new list containing only distinct elements from the original list. By comparing the sizes of the original and distinct lists, we can determine if there are any duplicates.
```
val distinctList = array.distinct()
if (array.size != distinctList.size) {
    println("Array has duplicate elements")
}
```
If the sizes are different, it means that the array has duplicate elements, and it will print "Array has duplicate elements".
Additionally, we can use the groupBy function to group the elements of the array based on their occurrences. If any group has more than one element, it means that there are duplicates.
```
val groupedMap = array.groupBy { it }
val duplicateGroups = groupedMap.filterValues { it.size > 1 }
if (duplicateGroups.isNotEmpty()) {
    println("Array has duplicate elements")
}
```
If duplicateGroups is not empty, it means that there are elements with multiple occurrences in the array, and it will print "Array has duplicate elements".
Finally, you can choose the approach that suits your needs and implement it in your Kotlin project to check if an array has duplicate elements.

These are the steps to check if an array has duplicate elements in Kotlin. You can choose any of the approaches mentioned above based on your requirements.