Array Example : Value & Type Paramaterization

scala> // Parameterize Class instance with Value & Type

scala>

scala> /*******************************************
     |    Creating & Initializing an Array #77
     | *******************************************/
     | //Option 1
     | // Here 'String'  is Parameterized Type
     | //      '2'       is a Parameterized Value
     | // Square Bracket ([]) is used to Parameterize a Type
     | val subject:Array[String] = new Array[String](2)
subject: Array[String] = Array(null, null)

scala> subject.update(0, "english")

scala> subject.update(1, "math")

scala>

scala> //Option 2

scala> val subject = new Array[String](3)
subject: Array[String] = Array(null, null, null)

scala> // During assignment Parenthesis calls the 'update()' method

scala> // passing both the Array index & value assigned

scala> subject(0) = "english"

scala> subject(1) = "math"

scala>

scala> // Option 3

scala> // Here Parenthesis in 'Array' calls the apply() factory

scala> // method of the Companion Object (Here Array is a

scala> // Companion Object rather than the Class)

scala> val subject = Array("english", "math")
subject: Array[String] = Array(english, math)


scala> /*******************************************
     |    Accessing an Array #77
     | *******************************************/
     |
     | //Option 1
     | for(i <- (0).to(1)) {
     |    // Note : Parenthesis is used to access an Array element
     |    //        unlike Square brackets that is used in Java
     |    //        #79
     |    print(subject.apply(i))
     | }
englishmath
scala>

scala> //Option 2

scala> // If a method ('to' in our case) takes only 1 parameter

scala> // '.' and Parenthesis cna be omitted (We should also have a

scala> // receiver for the method call...in our case 'i')

scala> for(i <- 0 to 1) {
     |    //Note here..the apply() method is called implicitly
     |    print(subject(i))
     | }
englishmath

Function Literal

A Function Literal is a function which do not have Name(#74)

val greetings=Seq("hello", "world")
greetings.foreach(x => println(x))

/*If the argument of the Functional Literal is specified an explicity 
type, then in should be wrapped in Parantheses #75*/
greetings.foreach(x:String=> println(x))
greetings.foreach((x:String)=> println(x))

/*If a function literal takes only 1 statement
and the statements only takes one argument,
then we can omit the argument #75 */
greetings.foreach(println) 

scala> val greetings=Seq("hello", "world")
greetings: Seq[String] = List(hello, world)
//Here x => println(x) is a Function that 
//do not have Name
scala> greetings.foreach(x => println(x))
hello
world

scala> 

scala> /*If the argument of the Functional Literal is specified an explicit 
     | type, then it should be wrapped in Parantheses #75*/
     | greetings.foreach(x:String=> println(x))
<console>:3: error: ')' expected but '(' found.
       greetings.foreach(x:String=> println(x))
                                           ^
<console>:3: error: ';' expected but ')' found.
       greetings.foreach(x:String=> println(x))
                                              ^

scala> greetings.foreach((x:String)=> println(x))
hello
world

scala> 

scala> /*If a function literal takes only 1 statement
     | and the statements only takes one argument,
     | then we can omit the argument #75 */
     | greetings.foreach(println) 
hello
world