What is a common use for the 'when' keyword in Kotlin?

The 'when' keyword in Kotlin is commonly used to evaluate multiple conditions in a concise and expressive way. It acts similarly to a switch statement found in other programming languages but offers more flexibility. You can use 'when' to compare a single value against different possible matches, making it a powerful tool for branching logic.

For example, you can use 'when' to execute different blocks of code based on the value of a variable. If you have an integer representing a day of the week, a 'when' expression can easily map that integer to a specific day string. Moreover, 'when' can also handle complex conditions, including checking for types, ranges, or arbitrary conditions, all in a single construct, enhancing code readability and maintainability.

Using 'when' improves the clarity of code, especially when you have multiple conditions to check against a single variable, making it a preferred choice in Kotlin for such scenarios.