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Displays all elements of the list in a string using a separator string. 34 35 36 37 38 39 40 41 42 43 44 45 def reverse: List[A] Returns new list with elements in reversed order. def sorted[B >: A]: List[A] Sorts the list according to an Ordering. def startsWith[B](that: Seq[B], offset: Int): Boolean Tests whether the list contains the given sequence at a given index. def sum: A Sums up the elements of this collection. def tail: List[A] Returns all elements except the first. def take(n: Int): List[A] Returns first n elements. def takeRight(n: Int): List[A] Returns last n elements. def toArray: Array[A] Converts the list to an array. def toBuffer[B >: A]: Buffer[B] Converts the list to a mutable buffer. def toMap[T, U]: Map[T, U] Converts this list to a map. def toSeq: Seq[A] Converts the list to a sequence. def toSet[B >: A]: Set[B] Converts the list to a set. 46 def toString(): String Converts the list to a string. Scala Sets Scala Set is a collection of pairwise different elements of the same type. In other words, a Set is a collection that contains no duplicate elements. There are two kinds of Sets, the immutable and themutable. The difference between mutable and immutable objects is that when an object is immutable, the object itself can't be changed. By default, Scala uses the immutable Set. If you want to use the mutable Set, you'll have to import scala.collection.mutable.Set class explicitly. If you want to use both mutable and immutable sets in the same, then you can continue to refer to the immutable Set as Set but you can refer to the mutable Set as mutable.Set. Following is the example to declare immutable Sets as follows: // Empty set of integer type var s : Set[Int] = Set() // Set of integer type var s : Set[Int] = Set(1,3,5,7) or TUTORIALS POINT Simply Easy Learning
var s = Set(1,3,5,7) While defining empty set, the type annotation is necessary as the system needs to assign a concrete type to variable. Basic Operations on Set: All operations on sets can be expressed in terms of the following three methods: Methods Head Tail isEmpty Description This method returns the first element of a set. This method returns a set consisting of all elements except the first. This method returns true if the set is empty otherwise false. Following is the example showing usage of the above methods: object Test { def main(args: Array[String]) { val fruit = Set("apples", "oranges", "pears") val nums: Set[Int] = Set() } } println( "Head of fruit : " + fruit.head ) println( "Tail of fruit : " + fruit.tail ) println( "Check if fruit is empty : " + fruit.isEmpty ) println( "Check if nums is empty : " + nums.isEmpty ) When the above code is compiled and executed, it produces the following result: C:/>scalac Test.scala C:/>scala Test Head of fruit : apples Tail of fruit : Set(oranges, pears) Check if fruit is empty : false Check if nums is empty : true C:/> Concatenating Sets: You can use either ++ operator or Set.++() method to concatenate two or more sets, but while adding sets it will remove duplicate elements. Following is the example to concatenate two sets: object Test { def main(args: Array[String]) { val fruit1 = Set("apples", "oranges", "pears") val fruit2 = Set("mangoes", "banana") // use two or more sets with ++ as operator var fruit = fruit1 ++ fruit2 println( "fruit1 ++ fruit2 : " + fruit ) // use two sets with ++ as method fruit = fruit1.++(fruit2) println( "fruit1.++(fruit2) : " + fruit ) TUTORIALS POINT Simply Easy Learning
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Scala Tutorial
Page 3 and 4:
ABOUT THE TUTORIAL Scala Tutorial S
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FLOATING POINT LITERALS ...........
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Scala Strings .....................
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CHAPTER 1 Scala Overview Scala, sho
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CHAPTER 2 Scala Environment Setup T
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$scala -version Scala code runner v
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} * This will print 'Hello World' a
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forSome If implicit import Lazy Mat
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CHAPTER 4 Scala Data Types Scala ha
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Characters must not necessarily be
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Variable Type Inference: When you a
Page 25 and 26: The access to f in class Sub is OK
Page 27 and 28: var a = 10; var b = 20; var c = 25;
Page 29 and 30: } } println("a && b = " + (a&&b) );
Page 31 and 32: a >>> 15 C:/> Assignment Operators:
Page 33 and 34: Here, operators with the highest pr
Page 35 and 36: } If the boolean expression evaluat
Page 37 and 38: Nested if...else Statement: It is a
Page 39 and 40: while loop do...while loop for loop
Page 41 and 42: Flow Diagram: Example: object Test
Page 43 and 44: When the above code is compiled and
Page 45 and 46: } } // for loop execution with mult
Page 47 and 48: Flow Diagram: Example: import scala
Page 49 and 50: Infinite Loop: A loop becomes infin
Page 51 and 52: } } return sum A function, which do
Page 53 and 54: When the above code is compiled and
Page 55 and 56: } When the above code is compiled a
Page 57 and 58: } logWithDateBound("message1" ) log
Page 59 and 60: CHAPTER 12 Scala Strings Consider t
Page 61 and 62: } } var str2 = "Tod"; println("Dot
Page 63 and 64: 23 24 25 26 27 28 29 30 31 32 33 34
Page 65 and 66: CHAPTER 13 Scala Arrays Scala provi
Page 67 and 68: C:/> Multi-Dimensional Arrays: Ther
Page 69 and 70: C:/> Scala Arrays Methods: Followin
Page 71 and 72: Scala Lists Scala Lists are quite s
Page 73 and 74: Creating Uniform Lists: You can use
Page 75: 13 14 15 16 17 18 19 20 21 22 23 24
Page 79 and 80: C:/> Scala Set Methods: Following a
Page 81 and 82: elements. 38 39 40 41 42 43 44 45 4
Page 83 and 84: use two maps with ++ as method colo
Page 85 and 86: 11 12 13 14 15 16 17 18 19 20 21 22
Page 87 and 88: val t = new Tuple3(1, "hello", Cons
Page 89 and 90: The method will return Some[Person]
Page 91 and 92: 6 7 8 9 10 11 12 13 14 def filter(p
Page 93 and 94: Scala Iterator Methods: Following a
Page 95 and 96: 38 39 40 41 42 43 44 45 46 47 48 49
Page 97 and 98: CHAPTER 15 Scala Classes & Objects
Page 99 and 100: } } println ("Point y location : "
Page 101 and 102: CHAPTER 16 Scala Traits A trait enc
Page 103 and 104: CHAPTER 17 Scala Pattern Matching P
Page 105 and 106: } // case class, empty one. case cl
Page 107 and 108: } When the above code is compiled a
Page 109 and 110: [0-9] Match any digit; same as [012
Page 111 and 112: CHAPTER 19 Scala Exception Handling
Page 113 and 114: CHAPTER 20 Scala Extractors An extr
Page 115 and 116: CHAPTER 21 Scala Files I/O Scala is
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