Kotlin keyword and operator

And Java contrast , take kotlin Unique keywords come first .

Hard keywords

keyword	meaning
val	Declare a read-only variable
var	Declare a variable
when	Start a when expression , similar Java Medium switch
as	For type conversion ; Specify an alias for the import
as?	Used for safe type conversion
fun	Declare a function
in	1. Appoint for Objects iterated in the loop ;2. As infix operator , Detect the interval of a value ;3. Mark a type parameter as inverse
!in	1. Use as infix expression , Detect that a value does not belong to an interval
is	Detect that a variable is of a specified type
!is	Detect that a variable is not of the specified type
typealias	Declare a type alias
interface	Declare an interface
break	Terminate the execution of the loop
class	Declare a class
continue	Continue to the next cycle
do	Post conditional loop ,do/while Use a combination of
else	A definition of if The branch taken when the expression does not satisfy the condition
false	Boolean type “ false ” value
for	Start a for loop
if	Start a if expression
null	Is a constant that represents an object reference that does not point to any object
object	Declare a class and its instances at the same time ,
package	Specifies the package of the current file
return	Return from the nearest layer function or anonymous function
super	Methods that reference the parent class ; The constructor of the parent class is called in the constructor
this	1. Reference the current recipient ;2. Call another constructor in the constructor
throw	Throw an exception
try	Start an exception handling block
while	Start a while loop

Soft keywords

The following symbols act as keywords in the applicable context , It can be used as an identifier in other contexts ：

keyword	meaning
by	agent , Delegate the implementation of the interface to another object ; Delegate the implementation of the property accessor to another object
constructor	Declare a constructor , When there are multiple constructors, you will use
delegate	Used as the target of annotation
dynamic	Refer to a Kotlin/JS Dynamic types in code
init	Start an initialization code block
where	Specify constraints for generic type parameters
field	Use in comments
file	Used as an annotation
finally	try A block that is always executed when a statement block exits
get	1. Declaring the property getter;2. Use in comments
set	1. Declaring the property setter;2. Use in comments
import	Import the declaration from another package into the current file