Scala Range

Scala山脉

A Range is a bounded series with a uniform interval with an upper and lower limit. The range literal is a numerical sequence of number ranging with a certain limit.

范围是一个有上限且下限均匀的有界序列。 范围文字是具有一定限制的范围内的数字的数字序列。

This defined sequence has many uses in programming like in easy initialization of the loop, sequence problems, etc.

此定义的序列在编程中有许多用途，例如在循环的轻松初始化，序列问题等中。

Methods to initialize a range

初始化范围的方法

There are multiple methods by which a range variable can be initialized. They are,

有多种方法可以用来初始化范围变量。 他们是，

1. By using "to" keyword

   通过使用“ to”关键字

   Syntax : var range_name = a to b 
   Example: var a = 3 to 6 // gives 3 , 4, 5, 6.
   
   

2. By using "by" keyword with others: Increases the interval

   通过与其他用户一起使用“ by”关键字：增加间隔

   Syntax : var range_name =  a until b by x
   Example: var a = 3 until 10 by 2 // gives 3, 5, 7, 9.
   
   

3. By using "range" keyword

   通过使用“范围”关键字

   Syntax : var range_name = range(a,b,x) 
   Example: var a = range(3,6,1)// gives 3 , 4, 5,6.
   
   

The range can also be directly initialized to a data structure like an array, list, vector, map. Methods to initialize range to an array:

范围也可以直接初始化为数据结构，例如数组，列表，向量，映射。 将范围初始化为数组的方法：

toarray Method

数组方法

var var_name = (2 to 6 ).toarray 

Using range method of array object

使用数组对象的范围方法

var var_name = Array.range(5 to 9)

In a similar way List and vector method works.

List和vector方法以类似的方式工作。

Sample code to illustrate use of Scala range

示例代码说明了Scala系列的用法

object myObject 
{ 
def rangeprint(a:Range){
println(a) 
println(a(1)) 
println(a.last) 
}
def main(args: Array[String]) 
{ 
val R1 = 3 to 6
val R2 = 3 until 7
var R3 = 3 to 11 by 2
var R4 = Range(3,45,4)
rangeprint(R1)
rangeprint(R2)	
rangeprint(R3)	
rangeprint(R4)
} 	
} 

Output

输出量

Range 3 to 6
4
6
Range 3 until 7
4
6
Range 3 to 11 by 2
5
11
inexact Range 3 until 45 by 4
7
43

翻译自: https://www.includehelp.com/scala/ranges-in-scala.aspx