scala不可变和可变_在Scala中将不可变地图转换为可变地图

scala不可变和可变

Map: Scala 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 ： Scala 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

Scala中不可变映射到可变映射的转换 (Immutable Map to Mutable Map Conversion in Scala)

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: https://www.includehelp.com/scala/convert-immutable-map-to-mutable-map.aspx

scala不可变和可变