In the above example, we used a map interface, and it will store the user inputs as key-value pairs. We can use mapOf() method for to set the key values and print them accordingly. Example #2 Code: packageone;funmain(args:Array<String>){val first=mapOf("siva"to1,1to"raman",'...
Example #2 Code: packageone;funmain(){println("Welcome to my domain its a first example regarding the kotlin mapOf() function")val second=mapOf("january"to1,"february"to2,"march"to3,"april"to4,"may"to5,"june"to6,"july"to7,"august"to8,"september"to9,"october"to10,"november"to...
但是,考虑到LiveData会调度到主线程触发这个特点,LiveData Extensions里提供的map,filter等同步转换操作符不适合做耗时操作,例如网络、IO等等。如果确有耗时操作的需求,LiveData Extensions里还提供了switchMap操作符,这是一个异步操作符,它会生成一个新的LiveData,合并到当前的数据流中。 另外,我们更主张使用多个LiveData...
In this example, the map function doubles each element of the collection. data class Number(val name: String, val value: Int) val li = listOf(Number("one", 1), Number("two", 2), Number("three", 3)) // it prints [one, two, three] println(li.map { it.name }) 1. 2. 3....
例如我们调用一个函数会使用: A.to(B) 这种结构,但是使用 infix 函数我们可以这么写:A to B,这种语法我们在讲 Map 的时候用过 //定义一个不可变 Map 集合 val map1 = mapOf("Apple" to 1,"Banana" to 2,"Orange" to 3, "Pear" to 4,"Grape" to 5) 1. 2.1)、在函数前面加上 infix 关键...
fun example() { val associations: MutableMap<String, Supplier<Interface>> = HashMap() associations["first"] = Supplier(::One) associations["second"] = Supplier(::Two) } interface Interface class One : Interface class Two : Interface kotlin Share Improve this question Follow edited Jul 29...
valnumbers=mutableListOf("one","two","three","four","five")numbers.map{it.length}.filter{it>3}.let{println(it)// 如果需要可以有更多的方法调用} 如果在代码块中只包含了一个已it作为参数的方法,你可以使用方法引用(::)来代替lambda。
Use onEach function: var exampleMap: MutableMap<Int, String> = mutableMapOf(1 to "One", 2 to "Two") println(exampleMap) exampleMap.onEach { exampleMap[it.key] = "${it.key}__${it.value}" } println(exampleMap) Output: {1=One, 2=Two} {1=1__One, 2=2__Two} onEach pe...
函数和方法是同一个概念,函数源于英语的function,而方法更多是指method。在Kotlin中function的叫法更加普遍,Java相反。 函数是代码的载体,在运行函数的时候它里面的代码会全部运行。main函数是一个特殊的函数,程序最开始运行的函数。Kotlin定义函数的方法如下: ...
The map() function has a counterpart function that may leverage the element’s index more conveniently. Namely, mapIndexed(), is perfect to use when the index of an element may be needed in the desired transformation.Here’s a simple example using the same basic Set collection from before,...