Property initialization using "by lazy" vs. "lateinit"

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In Kotlin, if you don't want to initialize a class property inside the constructor or in the top of the class body, you have basically these two options (from the language reference):

  1. Lazy Initialization

lazy() is a function that takes a lambda and returns an instance of Lazy<T> which can serve as a delegate for implementing a lazy property: the first call to get() executes the lambda passed to lazy() and remembers the result, subsequent calls to get() simply return the remembered result.``` public class Hello {

val myLazyString: String by lazy { "Hello" }

}


So, the first call and the subsequential calls, wherever it is, to `myLazyString` will return `Hello`

1. Late Initialization


> Normally, properties declared as having a non-null type must be initialized in the constructor. However, fairly often this is not convenient. For example, properties can be initialized through dependency injection, or in the setup method of a unit test. In this case, you cannot supply a non-null initializer in the constructor, but you still want to avoid null checks when referencing the property inside the body of a class.To handle this case, you can mark the property with the lateinit modifier:```
public class MyTest {
   
   lateinit var subject: TestSubject

   @SetUp fun setup() { subject = TestSubject() }

   @Test fun test() { subject.method() }
}

The modifier can only be used on var properties declared inside the body of a class (not in the primary constructor), and only when the property does not have a custom getter or setter. The type of the property must be non-null, and it must not be a primitive type. So, how to choose correctly between these two options, since both of them can solve the same problem?