scala中创建时间序列_在Scala中创建列表

男娘i 2023-03-05 09:41 16阅读 0赞

scala中创建时间序列

## 在Scala中列出 **(**List in Scala**)** ##

List is a collection of immutable data of the same type. It represents a LinkedList in Scala.

列表是相同类型的不可变数据的集合。 它代表Scala中的LinkedList。

### 在Scala中创建列表 **(**Creating List in Scala**)** ###

There are multiple ways to create a list. They are,

有多种创建列表的方法。 他们是，

1.  General Java-style programming method
    
    通用Java风格的编程方法
2.  Using fill method
    
    使用填充方法
3.  Using range method
    
    使用范围法
4.  Using tabulate method
    
    使用制表法
5.  Using lisp style of programming
    
    使用Lisp风格的编程

### 1)以Java风格的编程方法创建列表 **(**1) Creating List in Java-style programming method**)** ###

The general and most popular method to create a list in initializing the elements inside a curly bracket the same style is used to create the list in java, hence it is called the Java-style.

在大括号中初始化元素时，创建列表的一般方法和最受欢迎的方法是使用相同的样式在Java中创建列表，因此将其称为Java样式。

**Syntax:**

**句法：**

val list_name = List(element1, element2,...)

**Example:**

**例：**

object MyObject {
        
        def main(args: Array[String]) {
        
            println("Creating a List in Java Style")
            val mylist = List(10, 20, 10, 40, 10, 20, 90, 70)
            println("Element of the list:\n" + mylist)
        }
    }

**Output**

**输出量**

Creating a List in Java Style
    Element of the list:
    List(10, 20, 10, 40, 10, 20, 90, 70)

### 2)使用fill()方法在Scala中创建列表 **(**2) Creating a List in Scala using fill() method**)** ###

If you want to create a List of multiple elements with the same data, we will use the fill() method.

如果要创建具有相同数据的多个元素的列表，我们将使用fill()方法。

**Syntax:**

**句法：**

val list_name = List.fill(count)(element)

Here,

这里，

*  count is the number of elements of the List.
    
    count是列表中元素的数量。
 *  element is the element that is repeated in the list.
    
    element是在列表中重复的元素。

**Example:**

**例：**

object MyObject {
            
        def main(args: Array[String]) {
        
            println("Creating a List using fill method ")
            val mylist = List.fill(5)("includehelp")
            println("Element of the list:\n" + mylist)
        }
    }

**Output**

**输出量**

Creating a List using fill method 
    Element of the list:
    List(includehelp, includehelp, includehelp, includehelp, includehelp)

### 3)使用range()方法在Scala中创建列表 **(**3) Creating a List in Scala using range() method**)** ###

If you want to create a List with elements within a given range, we will use the range() method.

如果要创建具有给定范围内的元素的列表，我们将使用range()方法。

**Syntax:**

**句法：**

val list_name = List.range(start, end, step)

Here,

这里，

*  start: beginning value of the range.
    
    start ：范围的起始值。
 *  end: end value of the range.
    
    end ：范围的结束值。
 *  step: the step count i.e. element to be skipped in the List.
    
    step ：步数，即要在列表中跳过的元素。

**Example:**

**例：**

object MyObject {
            
        def main(args: Array[String]) {
        
            println("Creating a List using range method ")
            val mylist = List.range(10, 50, 5)
            println("Element of the list:\n" + mylist)
        }
    }

**Output**

**输出量**

Creating a List using range method 
    Element of the list:
    List(10, 15, 20, 25, 30, 35, 40, 45)

### 4)使用tabulate()方法在Scala中创建列表 **(**4) Creating a List in Scala using tabulate() method**)** ###

If you want to create a List with elements that are created passing a set of values to a function.

如果要使用创建的元素创建列表，则将一组值传递给函数。

**Syntax:**

**句法：**

val list_name = List.tabulate(count)(function)

Here,

这里，

*  count is count from 0 to count passed to function.
    
    count是从0到传递给函数的count的计数。
 *  function on which the count elements will be passed.
    
    传递计数元素的函数 。

**Example:**

**例：**

object MyObject {
            
        def main(args: Array[String]) {
        
            println("Creating a List using tabulate method")
            val mylist = List.tabulate(10)(n => n+1)
            println("Elements of the list:\n" + mylist)
        }
    }

**Output**

**输出量**

Creating a List using tabulate method
    Elements of the list:
    List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

### 5)以Lisp样式在Scala中创建列表 **(**5) Creating a List in Scala in Lisp style**)** ###

If you want to create a List using Lisp style programming using ::.

如果要使用Lisp样式编程通过::创建列表。

**Syntax:**

**句法：**

val list_name = element1 :: element2 :: Nil

Nil here is used to end the list.

这里的Nil用于结束列表。

**Example:**

**例：**

object MyObject {
        
        def main(args: Array[String]) {
        
            println("Creating a List using lisp style ")
            val mylist = "BMW S1000 RR" :: "Thunderbird 350" :: "Iron 883" :: Nil
            println("Elements of the list:\n" + mylist)
        }
    }

**Output**

**输出量**

Creating a List using lisp style 
    Elements of the list:
    List(BMW S1000 RR, Thunderbird 350, Iron 883)

> 翻译自: [https://www.includehelp.com/scala/creating-a-list.aspx][https_www.includehelp.com_scala_creating-a-list.aspx]

scala中创建时间序列

[https_www.includehelp.com_scala_creating-a-list.aspx]: https://www.includehelp.com/scala/creating-a-list.aspx