Today, we will learn about Scala arrays, how to declare and process them, and multidimensional arrays. We will also see how to create them with Range and concatenating them.<\/p>\n
So, let\u2019s begin our tutorial on Scala Array.<\/p>\n
When we want to hold a number of elements of the same kind in a collection, we use an array. An array is sequential and is of a fixed size.<\/p>\n
We can declare Scala arrays in two ways.<\/p>\n
We can create an array in Scala with default initial elements according to data type, and then fill in values later.<\/p>\n
scala> var a=new Array[Int](3) \/\/This can hold three elements\r\na: Array[Int] = Array(0, 0, 0)\r\nscala> a(1)\r\nres6: Int = 0\r\nscala> a(1)=2 \/\/Assigning second element\r\nscala> a\r\nres8: Array[Int] = Array(0, 2, 0)<\/pre>\nWe can also mention the type of Scala array when declaring it:<\/p>\n
scala> var a:Array[Int]=new Array[Int](3)\r\na: Array[Int] = Array(0, 0, 0)\r\nscala> a(4\/2)=3\r\nscala> a\r\nres10: Array[Int] = Array(0, 0, 3)<\/pre>\nb. Define Scala Array with Values<\/h4>\n
We can also define a Scala array specifying its values in place.<\/p>\n
scala> var a=Array(1,2,3)\r\na: Array[Int] = Array(1, 2, 3)\r\nscala> a(4)\r\njava.lang.ArrayIndexOutOfBoundsException: 4\r\n ... 28 elided\r\nscala> a(0)\r\nres12: Int = 1<\/pre>\nHow to Process an Array in Scala?<\/h3>\n
Since we know the type of elements and the size of the Scala array, we can use loop control structures to process an array. Let\u2019s take an example of processing Scala Array.<\/p>\n
To iterate over the array:<\/p>\n
scala> var a=Array(1,2,3)\r\na: Array[Int] = Array(1, 2, 3)\r\nscala> for(i<-a){\r\n | println(i)\r\n | }<\/pre>\n1
\n2
\n3<\/p>\nTo calculate the sum of all the elements:<\/p>\n
scala> var sum=0.0\r\nsum: Double = 0.0\r\nscala> for(i<-a){\r\n | sum+=i}\r\nscala> sum\r\nres2: Double = 6.0\r\nFinding the highest value from the array:\r\nscala> var max=a(0)\r\nmax: Int = 1\r\nscala> for(i<-a){\r\n | if(i>max){\r\n | max=i}\r\n | }\r\nscala> max\r\nres4: Int = 3<\/pre>\nConcatenating Arrays in Scala<\/h3>\n
We can append a Scala array to another using the concat() method. This takes the arrays as parameters- in order.<\/p>\n
scala> var a=Array(1,2,3)\r\na: Array[Int] = Array(1, 2, 3)\r\nscala> var b=Array(4,5,6)\r\nb: Array[Int] = Array(4, 5, 6)<\/pre>\nWe\u2019ll need to import the Array._ package<\/p>\n
scala> import Array._\r\nimport Array._<\/pre>\nNow, let\u2019s call concat().<\/p>\n
scala> var c=concat(a,b)\r\nc: Array[Int] = Array(1, 2, 3, 4, 5, 6)<\/pre>\nCreating a Scala Array with Range<\/h3>\n
The range() method will give us integers from the start to the end. We can also specify a step to denote the interval.<\/p>\n
We can use this to create an array to iterate on.<\/p>\n
scala> var a=range(2,15)\r\na: Array[Int] = Array(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)\r\nscala> var b=range(15,2,-2)\r\nb: Array[Int] = Array(15, 13, 11, 9, 7, 5, 3)<\/pre>\nScala Multidimensional Arrays<\/h3>\n
Why settle in two dimensions when we can have multiple? Sometimes, we may need more than two.<\/p>\n
scala> var a=ofDim[Int](3,3)\r\na: Array[Array[Int]] = Array(Array(0, 0, 0), Array(0, 0, 0), Array(0, 0, 0))\r\nNow, let\u2019s fill in some values.\r\nscala> for(i<-0 to 2){\r\n | for(j<-0 to 2){\r\n | a(i)(j)={i+j}\r\n | }\r\n | }\r\nscala> a\r\nres10: Array[Array[Int]] = Array(Array(0, 1, 2), Array(1, 2, 3), Array(2, 3, 4))<\/pre>\nSo, this was all about Scala Array Tutorial. Hope you like our explanation.<\/p>\n
Conclusion<\/h3>\n
With arrays in Scala, we can deal with a set of values of the same kind. Feel free to ask us any doubts in the comment section.<\/p>\n