scala 空列表_如何在Scala中展平列表列表？

r囧r小猫 2023-03-05 15:50 8阅读 0赞

scala 空列表

Flattening of List is converting a list of multiple List into a single List. To flatten List of List in Scala we will use the flatten method.

扁平化列表是将多个列表的列表转换为单个列表。 为了在Scala中扁平化List列表，我们将使用flatten方法。

**Syntax:**

**句法：**

val newList = list.flatten

**Program to flatten a list of list with numerical values**

**程序用数值拼合列表列表**

object MyClass {
        
        def main(args: Array[String]) {
        
            val ListofList = List(List(214, 56), List(6, 12, 34, 98))
            
            println("List of List: " + ListofList)
            
            println("Flattening List of List ")
            
            val list = ListofList.flatten
            
            println("Flattened List: " + list)
        }
    }

**Output**

**输出量**

List of List: List(List(214, 56), List(6, 12, 34, 98))
    Flattening List of List 
    Flattened List: List(214, 56, 6, 12, 34, 98)

The same flatten method can also be applied to convert sequence of sequence to a single sequence([Array][], list, Vector, etc.).

同样的展平方法也可以应用于将序列序列转换为单个序列( [数组][Array] ，列表，向量等)。

You can **convert list of lists to list of type strings** in two ways.

您可以**通过**两种方式**将列表列表转换为类型字符串列表** 。

Let's explore how to?

让我们探索如何？

**Program:**

**程序：**

object MyClass {
        
        def main(args: Array[String]) {
        
            val ListofList = List(List("Include", "Help"), List("Programming", "Tutorial"))
    
            println("List of List: " + ListofList)
    
            println("Flattening List of List ")
    
            val list = ListofList.flatten
    
            println("Flattened List: " + list)
        }
    }

**Output**

**输出量**

List of List: List(List(Include, Help), List(Programming, Tutorial))
    Flattening List of List 
    Flattened List: List(Include, Help, Programming, Tutorial)

Another way could split the list of list into character lists.

另一种方法可以将列表列表拆分为字符列表。

**Program:**

**程序：**

object MyClass {
        
        def main(args: Array[String]) {
        
            val ListofList = List("Include", "Help")
    
            println("List of List: " + ListofList)
    
            println("Flattening List of List ")
    
            val list = ListofList.flatten
    
            println("Flattened List: " + list)
        }
    }

**Output**

**输出量**

List of List: List(Include, Help)
    Flattening List of List 
    Flattened List: List(I, n, c, l, u, d, e, H, e, l, p)

> 翻译自: [https://www.includehelp.com/scala/how-to-flatten-a-list-of-list-in-scala.aspx][https_www.includehelp.com_scala_how-to-flatten-a-list-of-list-in-scala.aspx]

scala 空列表

[Array]: https://www.includehelp.com/scala/arrays-in-scala.aspx
[https_www.includehelp.com_scala_how-to-flatten-a-list-of-list-in-scala.aspx]: https://www.includehelp.com/scala/how-to-flatten-a-list-of-list-in-scala.aspx