Introduction
Like other languages, Go also provides a switch statement.
Switch statements are a shorter way to write long if ... else if statements.
To make a switch, we start by using the keyword switch followed by a value or expression.
We then declare each one of the conditions with the case keyword.
We can also declare a default case, that will run when none of the previous case conditions matched:
operatingSystem := "windows"
switch operatingSystem {
case "windows":
// do something if the operating system is windows
case "linux":
// do something if the operating system is linux
case "macos":
// do something if the operating system is macos
default:
// do something if the operating system is none of the above
}
One interesting thing about switch statements, is that the value after the switch keyword can be omitted, and we can have boolean conditions for each case:
age := 21
switch {
case age > 20 && age < 30:
// do something if age is between 20 and 30
case age == 10:
// do something if age is equal to 10
default:
// do something else for every other case
}
Instructions
In this exercise we will simulate the first turn of a Blackjack game.
You will receive two cards and will be able to see the face up card of the dealer.
All cards are represented using a string such as "ace", "king", "three", "two", etc.
The values of each card are:
| card |
value |
card |
value |
| ace |
11 |
eight |
8 |
| two |
2 |
nine |
9 |
| three |
3 |
ten |
10 |
| four |
4 |
jack |
10 |
| five |
5 |
queen |
10 |
| six |
6 |
king |
10 |
| seven |
7 |
other |
0 |
Note: Commonly, aces can take the value of 1 or 11 but for simplicity we will assume that they can only take the value of 11.
Depending on your two cards and the card of the dealer, there is a strategy for the first turn of the game, in which you have the following options:
- Stand (S)
- Hit (H)
- Split (P)
- Automatically win (W)
Although not optimal yet, you will follow the strategy your friend Alex has been developing, which is as follows:
- If you have a pair of aces you must always split them.
- If you have a Blackjack (two cards that sum up to a value of 21), and the dealer does not have an ace, a face card (Jack/Queen/King) or a ten then you automatically win.
If the dealer does have any of those cards then you'll have to stand and wait for the reveal of the other card.
- If your cards sum up to a value within the range [17, 20] you should always stand.
- If your cards sum up to a value within the range [12, 16] you should always stand unless the dealer has a 7 or higher, in which case you should always hit.
- If your cards sum up to 11 or lower you should always hit.
1. Calculate the value of any given card
Implement a function to calculate the numerical value of a card:
value := ParseCard("ace")
fmt.Println(value)
// Output: 11
2. Implement the decision logic for the first turn
Write a function that implements the decision logic as described above:
func FirstTurn(card1, card2, dealerCard string) string
Here are some examples for the expected outcomes:
FirstTurn("ace", "ace", "jack") == "P"
FirstTurn("ace", "king", "ace") == "S"
FirstTurn("five", "queen", "ace") == "H"
Learning Exercise
