CODEWITHSUNDEEP
scaladictionary
Aaron
Aaron

Reputation: 2305

Scala: get a value from a map using a variable?

I'm simply trying to get an Int value that's associated with a String key. I get:

error: type mismatch;
found   : Char
required: String
    score += tiles(letter)

from my code here:

val tiles = Map[String, Int](
    "a" -> 1,
    "b" -> 3,
    "c" -> 3,
    "d" -> 2
    // etc.
)

def main(args: Array[String]) {
    println("\nScrabble Calculator 1.0")
    println("Enter words on the commandline.")
    println("Use a '_' character for blank tiles.\n")

    for (w <- args)  // loop through each word
        if (w.length < 2)
            println(w + ": one-letter words disallowed in Scrabble")
        else
            calculate(w)
}

def calculate(w: String) {
    var score = 0
    for (letter <- w)
        score += tiles(letter)
    println(w + ": " + score + " points")
}

If I do "a" or "b" instead of letter, it works fine (it returns 1, or 3, or whatever).

Upvotes: 0

Views: 1493

Answers (2)

Ben
Ben

Reputation: 71485

tiles is a Map[String, Int].

calculate takes a String argument, w. It pulls individual characters out of w into letter, so letter is of type Char.

You then try to look up letter in tiles. letter is a Char, when tiles needs a String. This is precisely what the compiler is telling you with that error message.

Upvotes: 1

Aaron
Aaron

Reputation: 2305

Oh, jeez. It was a simple syntax problem. If you use ' instead of ", it is interpreted as a Char:

val tiles = Map[Char, Int](
    'a' -> 1,
    'b' -> 3,
    'c' -> 3,
    'd' -> 2,

Upvotes: 1

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