Practical Use Cases of Switch Statement in Scala

1. Catch blocks are Pattern Matches and is same as below code

    try {
        // logic
    } catch {
        case e: RuntimeException => "runtime"
        case e: NullPointerException => "npe"
        case _ => "something else"
    }

    // Catch blocks are Pattern Matches and is same as below code
    /*
    try {
        // logic
    } catch(e) {
    e match {
        case e: RuntimeException => "runtime"
        case e: NullPointerException => "npe"
        case _ => "something else"
        }
    }
     */

2. Generators are also based on pattern matching

val list = List(1, 2, 3, 4)
    val evenOnes = for {
        x <- list if x % 2 == 0 // GENERATOR
    } yield x
    println(evenOnes)

    val tuples = List((1, 2), (2, 3))
    val filterTuples = for {
        (first, second) <- tuples // extractor in this generator
    } yield first * second
    println(filterTuples)

3. Multi value definitons are based on PMs

val tuple = (1, 2, 3)
    val (a, b, c) = tuple
    println(b)

    val head :: tail = list
    println(head)
    println(tail)

4. Partial Functions are based on Pattern Matching

    val mappedList = list.map {
        case v if v % 2 == 0 => s"$v is even"
        case 1 => "One"
        case _ => "Something else "
    }
    println(mappedList)
    // Note: Partial Function is a literal inside {}

    // is same as
    val mappedList2 = list.map(x => x match {
        case v if v % 2 == 0 => s"$v is even"
        case 1 => "One"
        case _ => "Something else "
    })

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