本文共 1964 字,大约阅读时间需要 6 分钟。
scala不可变和可变
Map: is a collection that stores elements as key-value pairs. The key value for a map is always unique and is used to access the specific pair in the map.
Map : 是一个将元素存储为键值对的集合。 映射的键值始终是唯一的,用于访问映射中的特定对。
Immutable Map: is a map in which the number of elements cannot be altered also the values cannot be changed. It is defined in scala.collection.immutable.Map
不可变地图 :是一个地图,其中元素的数量不能更改,值也不能更改。 它在scala.collection.immutable.Map中定义
Mutable Map: is an editable map, i.e. the number of elements and values can be changed after the creation of the map. It is defined in scala.collection.mutable.Map
可变图 :是可编辑的图,即在创建图后可以更改元素和值的数量。 它在scala.collection.mutable.Map中定义
This method seems a little bit different but is a valid way to get elements of an immutable map to a mutable Map. This is by using the properties of a mutable map i.e. adding elements to the map.
该方法似乎有些不同,但是是将不可变映射的元素获取到可变Map的有效方法。 这是通过使用可变地图的属性,即向地图添加元素。
Program:
程序:
object MyObject { def main(args: Array[String]) { val immutableMap = Map (1 -> "scala" , 2 -> "Python" , 3 -> "JavaScript") println("Immutalbe Map : " + immutableMap) val mutableMap = collection.mutable.Map[Int, String]() mutableMap ++= immutableMap println("Mutalbe Map : " + mutableMap) }}
Output:
输出:
Immutalbe Map : Map(1 -> scala, 2 -> Python, 3 -> JavaScript)Mutalbe Map : HashMap(1 -> scala, 2 -> Python, 3 -> JavaScript)
Explanation:
说明:
In the above code, we have discussed how to convert immutable Map to mutable Map in Scala? We have created an immutable map named immutableMap. Then to convert this to a mutable map, we have created an empty mutable map named mutableMap to this map we have added values of the immutableMap using ++ operator.
在上面的代码中,我们讨论了如何在Scala中将不可变Map转换为可变Map? 我们创建了一个名为immutableMap的不可变映射。 然后将其转换为可变映射,我们创建了一个名为mutableMap的空可变映射,并使用++运算符添加了immutableMap的值。
翻译自:
scala不可变和可变
转载地址:http://aivzd.baihongyu.com/