Monday, 24 October 2016

SCALA BASICS DAY 2 Practice on 25 Oct 2016

Scala Day 2 Practice:
==============================================


-----------------------------------------------------
Functions in Scala:
------------------------------------------------------
1. anonymous functions
2. named functions
3. curried functions

( x : Int ) =>  { x + 1 }

val add = ( x : Int ) : Int =>  { x + 1 }

add(1)

add(10)

-----------------------------------------------------

scala> val add = ( x : Int ) =>  { x + 1 }
add: Int => Int = <function1>

scala> ( x : Int ) =>  { x + 1 }
res2: Int => Int = <function1>

scala> add(1)
res3: Int = 2

scala> add(10)
res4: Int = 11

-----------------------------------------------------

def add( x : Int ) = { x + 1 }

def add( x : Int ) : Int = { x + 1 }

scala> def add( x : Int ) = { x + 1 }
add: (x: Int)Int

scala> def add( x : Int ) : Int = { x + 1 }
add: (x: Int)Int

scala> add(1)
res5: Int = 2

scala> add(10)
res6: Int = 11

-----------------------------------------------------

val id = 1

if( id == 1) {
  println("condtion match")
} else {
 println("condtion doesn't match")
}

def validate(id : Int) = {
if( id == 1) {
  println("condtion match")
} else {
 println("condtion doesn't match")
}
}

validate(id)




scala> def validate(id : Int) = {
     | if( id == 1) {
     |   println("condtion match")
     | } else {
     |  println("condtion doesn't match")
     | }
     | }
validate: (id: Int)Unit

scala> validate(id)
condtion match

scala> val id = 2
id: Int = 2

scala> validate(id)
condtion doesn't match




-----------------------------------------------------

def factorial( n : Int ) : Int = {
 if ( n == 1 ) 1
 else n * factorial( n - 1 )
}

scala> def factorial( n : Int ) : Int = {
     |  if ( n == 1 ) 1
     |  else n * factorial( n - 1 )
     | }
factorial: (n: Int)Int

scala> factorial(1)
res14: Int = 1

scala> factorial(5)
res15: Int = 120

scala> factorial(6)
res16: Int = 720

-----------------------------------------------------

scala> 1 to 5
res17: scala.collection.immutable.Range.Inclusive = Range(1, 2, 3, 4, 5)

scala> 1 to 5 by 2
res18: scala.collection.immutable.Range = Range(1, 3, 5)

scala> 1 to 5 by 3
res19: scala.collection.immutable.Range = Range(1, 4)

scala> 1 until 5
res20: scala.collection.immutable.Range = Range(1, 2, 3, 4)

scala> 1 until 5 by 2
res21: scala.collection.immutable.Range = Range(1, 3)


-----------------------------------------------------
Scala Collections:
-------------------
1. scala.collection.immutable
2. scala.collection.mutable

var arr1 = Array(1,2,3,4,5)
var arr1 = Array[Int](1,2,3,4,5)

var arr2 = Array("anil", "venkat", "raj", "anvith", "rohith")
var arr2 = Array[String]("anil", "venkat", "raj", "anvith", "rohith")


var list1 = List("anil", "venkat", "raj", "anvith", "rohith")
var list1 = List[String]("anil", "venkat", "raj", "anvith", "rohith")

var set1 = Set("anil", "venkat", "raj", "anvith", "rohith")
var set1 = Set[String]("anil", "venkat", "raj", "anvith", "rohith")


var seq1 = Seq("anil", "venkat", "raj", "anvith", "rohith")
var seq1 = Seq[String]("anil", "venkat", "raj", "anvith", "rohith")

var vec1 = Vector("anil", "venkat", "raj", "anvith", "rohith")
var vec1 = Vector[String]("anil", "venkat", "raj", "anvith", "rohith")



val any1 = List(1, 2.5, true, "anil")
val any1 = List[Any](1, 2.5, true, "anil")

-----------------------------------------------------

scala> var arr1 = Array(1,2,3,4,5)
arr1: Array[Int] = Array(1, 2, 3, 4, 5)

scala> var arr1 = Array[Int](1,2,3,4,5)
arr1: Array[Int] = Array(1, 2, 3, 4, 5)

scala> var arr2 = Array("anil", "venkat", "raj", "anvith", "rohith")
arr2: Array[String] = Array(anil, venkat, raj, anvith, rohith)

scala> var arr2 = Array[String]("anil", "venkat", "raj", "anvith", "rohith")
arr2: Array[String] = Array(anil, venkat, raj, anvith, rohith)

scala> var list1 = List("anil", "venkat", "raj", "anvith", "rohith")
list1: List[String] = List(anil, venkat, raj, anvith, rohith)

scala> var set1 = Set("anil", "venkat", "raj", "anvith", "rohith")
set1: scala.collection.immutable.Set[String] = Set(raj, anvith, rohith, venkat, anil)

scala> val any1 = List(1, 2.5, true, "anil")
any1: List[Any] = List(1, 2.5, true, anil)


-----------------------------------------------------

scala> list1.foreach(println)
anil
venkat
raj
anvith
rohith

scala> any1.foreach(println)
1
2.5
true
anil


scala> list1.foreach(println)
anil
venkat
raj
anvith
rohith

scala> list1.foreach(x => println(x))
anil
venkat
raj
anvith
rohith

scala> list1.foreach((x : String) => { println(x) })
anil
venkat
raj
anvith
rohith


scala> for(x <- list1) println(x)
anil
venkat
raj
anvith
rohith




scala> for(x <- 1 to 6) println(x)
1
2
3
4
5
6

scala> for(x <- 1 to 6 by 2) println(x)
1
3
5


scala> for(x <- 1 to 6) { if( x % 2 == 0 ) println(x) }
2
4
6

scala> for(x <- 1 to 6 if x % 2 == 0) println(x)
2
4
6



scala> val op = for(x <- 1 to 6 if x % 2 == 0) yield x
op: scala.collection.immutable.IndexedSeq[Int] = Vector(2, 4, 6)

scala> op.foreach(println)
2
4
6


-----------------------------------------------------

def factorial( n : Int ) : Int =  {
 var res = 1
 for ( x <- 1 to n )  res = res * x
 res
}


factorial(1)

factorial(5)


scala> def factorial( n : Int ) : Int =  {
     |  var res = 1
     |  for ( x <- 1 to n )  res = res * x
     |  res
     | }
factorial: (n: Int)Int

scala> factorial(1)
res34: Int = 1

scala> factorial(5)
res35: Int = 120

-----------------------------------------------------
curried functions:
------------------------------------------------------
def add( x : Int, y : Int ) : Int  = { x + y }

add(1,2)

def add( x : Int )( y : Int ) : Int  = { x + y }

add(1)(2)


def addOne(y : Int) = add(1)(y)
def addTwo(y : Int) = add(2)(y)

-----------------------------------------------------

scala> def add( x : Int, y : Int ) : Int  = { x + y }
add: (x: Int, y: Int)Int

scala> add(1,2)
res36: Int = 3

scala> def add( x : Int )( y : Int ) : Int  = { x + y }
add: (x: Int)(y: Int)Int

scala> add(1)(2)
res37: Int = 3


scala> def addOne(y : Int) = add(1)(y)
addOne: (y: Int)Int

scala> def addTwo(y : Int) = add(2)(y)
addTwo: (y: Int)Int

scala> addOne(5)
res38: Int = 6

scala> addTwo(5)
res39: Int = 7


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