use type deck and create a method to print cards go run main.go deck.go.

create a newDeck function.

Range of slice sliceVar[startIndexIncluding:upToNotIncluding] fruits := []{"apple", "banana", "kiwi"} fruits[0:2] // apple, banana is equivalent to fruits[:2] add deck function which returns 2 values of type deck.

func writeFile(filename string, data []byte, perm os.FileMode) error our challenge is to extract data - convert deck to []byte type conversion []byte("Hi there") - converts a string to slice of bytes deck -> []byte deck -> []string -> join to a single string -> []byte func readFile(filename string) ([]byte, error).

shuffle cards using random number generator.

create deck_test.go (with _test.go suffix) file run: go test.