A complete guide to null safety in Kotlin

Kotlin's null safety feature, a standout aspect of the language since its inception, addresses the common issue of null reference exceptions encountered in programming by distinguishing between nullable and non-nullable types. Unlike Java, where variables are nullable by default and can lead to runtime errors, Kotlin requires explicit declaration of nullable types using a question mark, thereby preventing null values unless specified. This strict null-safety is supported by several Kotlin operators, including the safe call operator (?.), the Elvis operator (?:), and the not-null assertion operator (!!), each offering advanced methods to handle nullability effectively. These operators facilitate the execution of actions conditionally based on null checks, provide default values when nulls are encountered, and ensure non-null assumptions when the programmer is certain of a variable's state. Through these mechanisms, Kotlin not only enhances code reliability and safety but also simplifies handling nullable types, offering a robust solution to a long-standing programming challenge.