Using Star Projections in Kotlin: Benefits and Usage

When Should We Use Star Projections in Kotlin?

Star projections are a feature of Kotlin that allow for generic type parameters to be used in places where a specific type cannot be specified. For example, say we have a class that takes in two parameters of type T and U, but they must both be of the same type. In this case, we would use a star projection to indicate that the two parameters can be of any type, as long as they are both the same.

Star projections can be particularly useful when we are dealing with collections or arrays of unknown types. For example, say we want to map an array of values to another type, but we don't know what type the array contains. In this case, we can use a star projection to indicate that it can contain any type, but all elements must be the same type. This allows us to write more generic code which can be used with a wider variety of data types.

Star projections can also be used to simplify the syntax of certain operations, such as creating a new instance of a generic type. For example, if we are creating a new List of type T, we can use the star projection syntax to indicate that the list can contain any type, as long as all elements are the same type. This simplifies the syntax and makes it easier to understand.

In summary, star projections can be used in a variety of situations where a specific type cannot be specified. They are particularly useful when dealing with collections and arrays, and can be used to simplify the syntax of certain operations. When used correctly, star projections can make code more efficient and easier to understand.