Can you list the types of delegates used in Kotlin?

In Kotlin, delegates are used to delegate the implementation of properties or behaviors. Main types of delegates:

• Standard delegates:

  • lazy — lazy initialization of a property when it is first accessed.
  • observable — allows tracking changes to a property's value via a callback.
  • vetoable — similar to observable, but allows canceling the change.

• Delegates for property storage:

  • notNull — a property that must be initialized before first use, otherwise it throws an exception.

• Delegates for interface delegation:

  • Using the keyword by to delegate the implementation of an interface to another object.

Example of using lazy:

val lazyValue: String by lazy {
    println("Calculating value")
    "Hello"
}

Thus, delegates in Kotlin allow convenient management of property behaviors and delegation of implementation.