如何在Scala中的数组列表中获取两个元素的总和(How to get the sum of two elements in a list of Arrays in Scala)

 您好，并提前感谢您花时间阅读本文。 
 
 我正在Scala中编写一段代码来读取数据文件，并生成一些聚合。 为简单起见，我们假设内容类似于以下内容（记录以制表符分隔）： 
 
 
 
 01/12/2015 JACK M 21XYZ 56 200 
 
 
 01/14/2015 JOHN M 22ABS 34 145 
 
 
 我想将最后两个数字相乘并将它们与第二个项目（Name）一起存储，然后运行一些统计数据(min, max, top 10, etc.) 
 
 到目前为止我采取的步骤： 
 
 1-阅读文件 
 
    val dat = scala.io.Source.fromFile("abs.txt")
 
 2-将内容放入列表中 
 
    val datList = try dat.getLines.toList finally dat.close
 
 3-将每个字符串拆分为一个字符串数组 
 
    val datArray = datList.map(_.split('\t'))
 
 在这些步骤之后，我有一个数组字符串数组。 我被困在这一点上。 我不知道如何计算每个数组的最后两个元素的乘法并将结果存储在地图中并将名称作为键。 
 
 当我尝试类似的东西 
 
    val res = datArray.map(x => x(4).toInt * x(5).toDouble)
 
 它返回一个单位，我无法用它做任何事情。 
 
 如果你能说清楚，我将不胜感激。 
 
 我在下面的链接中找到了类似的东西，但是在两个独立的数组之间，这似乎更简单。 
 
 Scala中数组的元素总和 
 
 谢谢， 
 
 萌 

Hello and thanks in advance for taking the time reading this.
 
I am writing a piece of code in Scala to read a data file, and produce a couple of aggregations. For the sake of simplicity let's assume the contents are something like the following(the records are tab delimited):
 
 
 
01/12/2015 JACK M 21XYZ 56 200
 
 
01/14/2015 JOHN M 22ABS 34 145
 
 
I want to multiply the last two numbers and store them along with the second item (Name) and then run some statistics (min, max, top 10, etc.)
 
Steps I have taken so far:
 
1- Read the file
 
    val dat = scala.io.Source.fromFile("abs.txt")
 
2- Put the contents in a list
 
    val datList = try dat.getLines.toList finally dat.close
 
3- Split each string into an array of Strings
 
    val datArray = datList.map(_.split('\t'))
 
after these steps I have an array of Array of strings. I am stuck at this point. I don't know how I can calculate the multiplication of the last two elements of each array and store the results in a map and have the name as key.
 
When I try something like
 
    val res = datArray.map(x => x(4).toInt * x(5).toDouble)
 
it returns a Unit and I cannot do anything with it.
 
I would appreciate it if you can shed some light.
 
I found something similar in the following link, however that is between two separate arrays which seems to be simpler.
 
Element-wise sum of arrays in Scala
 
Thanks,
 
Moe

原文：https://stackoverflow.com/questions/44570376