In Kotlin, to achieve functionality equivalent to Python's `str.split(".")[0]`, you can use the `split` function along with the `first` function or indexing. The `split` function in Kotlin also takes a delimiter and splits a string into a list of strings, similar to Python's `split`. Here are a couple of ways to split a string by a period and get the first element: Using `split` and `first`: ```kotlin val result = myString.split(".")[0] // OR val result = myString.split(".").first() ``` Using `substringBefore`: ```kotlin val result = myString.substringBefore(".") ``` Here's an example with both methods in action: ```kotlin fun main() { val myString = "example.com" // Method 1: Using split and indexing val result1 = myString.split(".")[0] println(result1) // Output: example // Method 2: Using split and first val result2 = myString.split(".").first() println(result2) // Output: example // Method 3: Using substringBefore val result3 = myString.substringBefore(".") println(result3) // Output: example } ``` The `substringBefore` method is more concise and directly expresses the intent of getting the substring before the first occurrence of the delimiter, so it could be considered more idiomatic in Kotlin for this particular case. Remember that if the string does not contain the delimiter and you use `substringBefore`, you'll get the original string as the result. On the other hand, if you use `split`, you'll also get a list with the original string as its only item, and accessing the first element `[0]` will return the full string as well. Choose the method that best fits the context and readability preferences for your code.