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How to count the number of words in a string in Kotlin

How to count the number of words in a string in Kotlin.

Here is a step-by-step tutorial on how to count the number of words in a string in Kotlin:

Step 1: Create a Kotlin function to count words​

To start, we need to create a function that will take a string as input and return the count of words in that string. Let's call this function countWords. 

fun countWords(input: String): Int {
    // Function body goes here
}

Step 2: Split the string into words​

Inside the countWords function, we need to split the input string into individual words. Kotlin provides a convenient method called split that splits a string into an array of substrings based on a delimiter. In our case, we can split the string using whitespace as the delimiter.

fun countWords(input: String): Int {
    val words = input.split(" ")
}

Step 3: Count the number of words​

Now that we have an array of words, we can simply return the count of elements in that array using the size property.

fun countWords(input: String): Int {
    val words = input.split(" ")
    return words.size
}

Step 4: Handle edge cases​

There are a few edge cases that we should consider. For example, if the input string is empty or contains only whitespace, we should return 0. We can add a simple check at the beginning of the function to handle these cases.

fun countWords(input: String): Int {
    if (input.isBlank()) {
        return 0
    }
    
    val words = input.split(" ")
    return words.size
}

Step 5: Test the function​

To ensure our function is working correctly, we should test it with different input strings. Here are a few examples:

fun main() {
    val input1 = "Hello world"
    val input2 = "This is a test"
    val input3 = "   "
    
    println(countWords(input1))  // Output: 2
    println(countWords(input2))  // Output: 4
    println(countWords(input3))  // Output: 0
}

That's it! You now have a function that can count the number of words in a string in Kotlin. Feel free to use this function in your own projects or modify it as needed.