Kotlin parameter confusions, kotlin Parameter

Kotlin parameter confusions, kotlin Parameter
The literal function is enclosed in braces and the parameter is declared before (the parameter type can be omitted). The function body is after->.

Parameter (T)-> R

/*** Map function maps a value to another value * map accepts a function, which has a parameter T */inline fun Array
 
  
. Map (transform :( T)-> R): List
  
   
{Return mapTo (ArrayList
   
    
(Size), transform)} val list = listOf (1, 2, 3, 4) val newList = list. map {it-> it % 2 = 0}/*** result: newlist = [false, true, false, true] * There is only one parameter, and the brackets can be omitted, the default it parameter */
   
  
 

The map function also accepts a function transform. The transform converts the T type in the map to R, and finally submits it to the mapto function for polling and execution of the transform. Finally, the entire set is converted into a map of R.

Parameter ()-> T

/*** ()-> T: a function of the T type is returned if no parameter exists */fun
 
  
F (body :()-> T ){}
 

(T, T)-> Boolean

/*** (T, T)-> Boolean: receives two T types and returns a Boolean value */fun max
 
  
(Collection: Collection
  
   
, Less: (T, T)-> Boolean): T? {Var max: T? = Null for (it in collection) // less is used as the function if (max = null | less (max !!, It) max = it return max}
  
 

The anonymous function has no name. Other syntaxes are similar to common functions.

var test3= fun(x:Int,y:Int):Int=x+yvar test4= fun(x:Int,y:Int):Int{    return  x+y}