1),Combine("b",2),Combine("c",3),Combine("a",4))val mapOfList=list.associateBy({it.alpha},{it.num})println(mapOfList)val changed=list.groupBy({it.alpha},{it.num})println(changed)} 您可以先按alpha对列表进行分组，然后将值映射到
我们使用map的keySet()方法获取所有键,并从中创建一个ArrayList键列表。同样,我们使用map的values()方法获取所有值,并从中创建一个ArrayList valueList。 以下是等效的Java代码:用于将map转换为list的Java程序。 Kotlin 实例大全 Kotlin 实例大全
First, let’s convert DEV_MAP to one list. 3.1. Getting a List of Map.Entry In Kotlin, map.entries gives us a read-only Set of all entries in the map. Then, we can use toList() to convert the set to a list: val result = DEV_MAP.entries.toList() assertEquals(DEV_MAP.size,...
Similarly, we create a list of pairs that contain anullvalue. Subsequently, we supply thefilter()method with a predicate function that removes any pair with anullvalue. Finally, we convert the list to a map after filtering using thetoMap()method. ...
一切皆是映射:詳解 Kotlin Map 集合類 map's size var mp = mapOf(1 to "aone", 2 to "two", 3 to "three") println(mp.size) // 3 1. 2. get key value println(mp[2]) // two 1. for iterator for ((k, v) in mp) {
inline 关键字适合修饰不太复杂的但会频繁调用的函数。所以 Kotlin 自带的操作符都是 inline 函数,我们如果要自定义一个操作符,也是需要修饰为 inline 函数。如下就是自定义了一个 convert 操作符,功能类似集合中的 map 函数。 代码语言:javascript 代码运行次数:0 ...
Cmdb.ListRequest.newBuilder().setProduct(cmdbProduct).build() ).productsList.map{product-> CmdbProductConverterImpl().convertToCmdbProduct(product) } 1. 2. 3. 4. 5. 上面的代码转化为一句话 CmdbProductConverterImpl().convertToCmdbProduct(product) ...
val capitols = listOf("England" to "London", "Poland" to "Warsaw") capitols.forEach { (country, city) -> println("Capitol of $country is $city") } 请注意,Kotlin 通过提供一组接口和辅助方法(List与MutableList,Set与Set与MutableSet,Map与MutableMap等)区分可变和不可变集合: ...
// create a graphics overlay to show the polygon, tapped location, and nearest vertex/coordinate val graphicsOverlay = GraphicsOverlay( listOf( polygonGraphic, tappedLocationGraphic, nearestCoordinateGraphic, nearestVertexGraphic ) ) val arcGISMap by mutableStateOf( ArcGISMap(statePlaneCaliforniaZone5Spati...
// .useMaxShardingQueryLimit(2,ExecuteMethodEnum.LIST,ExecuteMethodEnum.ANY,ExecuteMethodEnum.FIRST);} }//分片时间路由规则按月然后bean分片属性就是LocalDateTime也可以自定义实现publicclassTopicShardingTimeTableRouteextendsAbstractMonthTableRoute<TopicShardingTime>{@OverrideprotectedLocalDateTimeconvertLocalDateTime(...