kotlin not among Java wording

kotlin not among Java wording

Constructor

• Java class constructor and the same name, Kotlin using constructorFIG.
• No public constructor in Kotlin modification, because the default visibility is public.

init

final

• Member variable val for read-only
• The default is the type parameter val
• Local variables

val custom getter

static property/function

• object (singleton, and implements the interface inheritance, anonymous class)

• companion object

top-level property/function声明

constant

• Kotlin constants must be declared in the object (including the associated objects) or "top-level top-level" because constants are static.
• Kotlin new modified constant constkeyword.
• Kotlin only primitive types and String types can be declared as constants.

Arrays and collections

• Array:
  • Kotlin in the array has a generic class, create a function is a generic function, and aggregate data types.
  • Values ​​and modify
  • It does not support covariant
• set
  • Kotlin and Java as there are three collection types: List, Set, and Map
  • Values ​​and modify
  • Variable set / set immutable
  • In addition to the set of Kotlin also introduces a new type of container Sequence, and it is Iterablethe same as used to iterate through a set of data and can be processed for each specific element

Visibility modifiers

• public: Open, maximum visibility, where can reference.
• private: Private, minimal visibility, visible in visible and can be divided into classes according to different files declared position.
• protected: Protection equivalent to private+ subclass visible.
• internal: Internal, visible only within the module.

reference

kaixue.io