scala 数组合并
Scala | 合并两个数组 (Scala | Merging two arrays)
Arrays are important data structures in programming and there may arise times when we have two different arrays and we need to merge them into one for processing. This is the case when you need array concatenation which is the process to merge to arrays by appending the elements of the second array after the elements of the first array.
数组是编程中重要的数据结构，当我们有两个不同的数组并且需要将它们合并为一个数组进行处理时，可能会出现这种情况。 在需要数组级联的情况下就是这种情况，这是通过将第二个数组的元素追加到第一个数组的元素之后而合并到数组的过程。
Arrays in Scala are generally immutable, so we need to create a new array that will store the concatenated array in Scala. Or another method could be creating mutable arrays that will save memory.
Scala中的数组通常是不可变的，因此我们需要创建一个新数组，该数组将在Scala中存储级联数组。 或者另一种方法是创建可节省内存的可变数组。
For merging two arrays Scala provides you multiple methods and we will discuss them one by one in this article.
为了合并两个数组，Scala为您提供了多种方法，我们将在本文中逐一讨论。
1)使用concat()方法 (1) Using the concat() method)
In Scala, there is a method named concat() that is used to concatenate two arrays.
在Scala中，有一个名为concat()的方法用于连接两个数组。
Syntax:
句法：
concat(array_1, array_2)
This method returns an array which is a concatenated array.
此方法返回一个数组，该数组是一个级联数组。
Program to concatenate two arrays using concat() method
程序使用concat()方法连接两个数组
object myObject {
def main(args: Array[String]) {
val array1 = Array(56, 12, 67)
print("Array 1: ")
for(i <- 0 to array1.length-1)
print(array1(i)+" ")
val array2 = Array(83, 45, 90)
print("\nArray 2: ")
for(i <- 0 to array2.length-1)
print(array2(i)+" ")
val array3 = Array.concat(array1, array2)
print("\nMerged array: ")
for(i <- 0 to array3.length-1)
print(array3(i)+" ")
}
}
Output
输出量
Array 1: 56 12 67
Array 2: 83 45 90
Merged array: 56 12 67 83 45 90
2)使用++方法 (2) Using the ++ method)
To merge two arrays into one ++ method can also be used.
将两个数组合并为一个++方法也可以使用。
Syntax:
句法：
array1 ++ array2
This will return the merge array.
这将返回合并数组。
Program to concatenate two arrays using ++ method
程序使用++方法连接两个数组
object myObject {
def main(args: Array[String]) {
val array1 = Array("Include", "Help")
print("Array 1: ")
for(i <- 0 to array1.length-1)
print(array1(i)+" ")
val array2 = Array("Learn", "Programming")
print("\nArray 2: ")
for(i <- 0 to array2.length-1)
print(array2(i)+" ")
val array3 = array1 ++ array2
print("\nMerged array: ")
for(i <- 0 to array3.length-1)
print(array3(i)+" ")
}
}
Output
输出量
Array 1: Include Help
Array 2: Learn Programming
Merged array: Include Help Learn Programming
合并两个可变数组(arrayBuffers) (Merging two mutable arrays (arrayBuffers))
We can assign the concatenated array to any of the existing arrays when they are mutable. Both methods, concat() and ++ apply to ArrayBuffer also. A method assignment method can also be applied to the ArrayBuffer which is +=.
当它们可变时，我们可以将级联数组分配给任何现有数组。 concat()和++这两种方法也适用于ArrayBuffer 。 方法分配方法也可以应用于+ =的ArrayBuffer 。
Program to concatenate two ArrayBuffer into one
程序将两个ArrayBuffer连接为一个
import scala.collection.mutable.ArrayBuffer
object myObject {
def main(args: Array[String]) {
val array1 = ArrayBuffer(12, 43, 54)
print("Array 1: ")
for(i <- 0 to array1.length-1)
print(array1(i)+" ")
val array2 = ArrayBuffer(465, 787, 99)
print("\nArray 2: ")
for(i <- 0 to array2.length-1)
print(array2(i)+" ")
array1 ++= array2
print("\nMerged array: ")
for(i <- 0 to array1.length-1)
print(array1(i)+" ")
}
}
Output
输出量
Array 1: 12 43 54
Array 2: 465 787 99
Merged array: 12 43 54 465 787 99
翻译自: https://www.includehelp.com/scala/program-to-merge-two-arrays-or-array-buffer.aspx
scala 数组合并
