Scala Tutorial: Immutable variables (val) and value types

Want to learn more? Take the full course at https://learn.datacamp.com/courses/introduction-to-scala at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Let's define variables and explore types now. First, we need more details on the game of Twenty-One for our program. The rules you need to know: there is a deck of cards. Each card has a point value. 2s are worth 2, 3s 3, etc. through 10. Face cards are worth 10. Aces are worth 1 or 11, player's choice. Each player is dealt two cards to start, with the option to "hit" for another card or to "stay" otherwise. The aim and name of the game: get 21 points or as close to it as possible. If you exceed 21, you "bust" and can't win. Scala has two kinds of variables: vals and vars. vals are immutable, which means once initialized, vals can't be reassigned. In Twenty-One, a val is like any non-ace card. The value of the 4 of hearts will always be 4 points. One way to define the val fourHearts is by typing val fourHearts colon Int, then equals 4. If you're familiar with Java, a val is kind of like a final variable. Since fourHearts is a val, the Scala interpreter yells at us when we try to reassign it. Error: reassignment to val. These are all nine of Scala's value types. You saw fourHearts was an Int. All variables have types. For data-related tasks, the four most common types are Double, Int, Boolean, and String. Double is the default floating point value type that Scala offers. Ignore these technical definitions if they don't mean anything to you now. We won't need Double for our program, so here's an example using pi. 3.14 is a Double. Scala nudges us to use Double, and throws a type mismatch error if we give type Float to the value 3.14. One reason for the nudge: Double is more precise than Float. Double stores pi to 15 points beyond the decimal. Float, specified by adding an f at the end, stores pi to 7 points. Int is an integer. These range from neg