Task4-RandomCards

April 8, 2024

Deadline: Apr 19 (inclusive)

Task 4

Invoking Math.random() returns a (pseudo)random number of type double from the half-open interval [0, 1). Use this generator to draw cards from a standard deck. First, draw an integer from the interval [1, 4] (corresponding to suit: clubs, diamonds, hearts, spades) and then another number from the interval [2, 14] (deuce, trey, four, five, . . . , ten, Jack, Queen, King, Ace). Using the switch expression, define strings describing cards and display five such random cards on the console.

For example, the following program

public class Cards {
    public static void main(String[] args) {
        for (int i = 0; i < 5; ++i) {
            /*
            * Define two integers using only Math.random():
            * col is a random integer from range [1, 4]
            * rnk is a random integer from range [2, 14]
            */

            String color = switch(col) {
                // ...
            };

            String rank = switch(rnk) {
                // ...
            };

            System.out.println(rank + " of " + color);
        }
    }
}

could print

Five of Spades  
Queen of Clubs  
Seven of Diamonds  
Deuce of Hearts  
Eight of Hearts  

Solution

Replit V1 (with switch expression) Replit V2 (without switch expression)

public class RandomCards {
    public static void main(String[] args) {
        for (int i = 0; i < 5; ++i) {
            // Generate random integers for suit and rank
            int col = (int) (Math.random() * 4) + 1; // 1 to 4 (clubs, diamonds, hearts, spades)
            int rnk = (int) (Math.random() * 13) + 2; // 2 to 14 (deuce to Ace)

            // Define strings for suit and rank
            String color = switch (col) {
                case 1 -> "Clubs";
                case 2 -> "Diamonds";
                case 3 -> "Hearts";
                case 4 -> "Spades";
                default -> "Unknown";
            };

            String rank = switch (rnk) {
                case 2 -> "Deuce";
                case 3 -> "Trey";
                case 4, 5, 6, 7, 8, 9, 10 -> String.valueOf(rnk);
                case 11 -> "Jack";
                case 12 -> "Queen";
                case 13 -> "King";
                case 14 -> "Ace";
                default -> "Unknown";
            };

            System.out.println(rank + " of " + color);
        }
    }
}

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