How to number numbers in the list in Kotlin

To number the numbers in a list in Kotlin, you can follow these steps:

  1. Create a list of numbers: First, create a list of numbers that you want to number. For example, you can create a list of integers like this:

kotlin val numbers = listOf(10, 20, 30, 40, 50)

  1. Initialize a variable to keep track of the index: Declare a variable to keep track of the current index while iterating over the list. You can initialize it to 1 since we want to start numbering from 1.

kotlin var index = 1

  1. Use the map function to transform the list: The map function allows you to transform each element in the list. Iterate over the list using the map function and transform each element by appending the index to it.

kotlin val numberedNumbers = numbers.map { number -> val numberedNumber = "$index. $number" index++ numberedNumber }

In the above code, we use the lambda expression { number -> ... } to specify the transformation for each element. Inside the lambda, we create a new variable numberedNumber by appending the index and the original number. After that, we increment the index.

  1. Print the numbered list: Finally, you can print the numbered list to see the result.

kotlin numberedNumbers.forEach { println(it) }

The forEach function iterates over each element in the numberedNumbers list and prints it.

When you run the above code, you will see the list of numbers with their corresponding numbers:

1. 10
2. 20
3. 30
4. 40
5. 50

This approach allows you to number the numbers in a list while explaining each step.