add: exercises and quiz for appending and slicing

16-slices/exercises/14-slicing-by-args/main.go

@@ -0,0 +1,109 @@
+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Slicing by arguments
+//
+//   We've a []string, you will get arguments from the command-line,
+//   then you will print only the elements that are requested.
+//
+//   1. Print the []string (it's in the code below)
+//
+//   2. Get the starting and stopping positions from the command-line
+//
+//   3. Print the []string slice by slicing it using the starting and stopping
+//      positions
+//
+//   4. Handle the error cases (see the expected output below)
+//
+//   5. Add new elements to the []string slice literal.
+//      Your program should work without changing the rest of the code.
+//
+//   6. Now, play with your program, get a deeper sense of how the slicing
+//      works.
+//
+//
+// EXPECTED OUTPUT
+//
+//  go run main.go
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    Provide only the [starting] and [stopping] positions
+//
+//
+//  (error because: we expect only two arguments)
+//
+//  go run main.go 1 2 4
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    Provide only the [starting] and [stopping] positions
+//
+//
+//  (error because: starting index >= 0 && stopping pos <= len(slice) )
+//
+//  go run main.go -1 5
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    Wrong positions
+//
+//
+//  (error because: starting <= stopping)
+//
+//  go run main.go 3 2
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    Wrong positions
+//
+//
+//  go run main.go 0
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Normandy Verrikan Nexus Warsaw]
+//
+//
+//  go run main.go 1
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Verrikan Nexus Warsaw]
+//
+//
+//  go run main.go 2
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Nexus Warsaw]
+//
+//
+//  go run main.go 3
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Warsaw]
+//
+//
+//  go run main.go 4
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    []
+//
+//
+//  go run main.go 0 3
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Normandy Verrikan Nexus]
+//
+//
+//  go run main.go 1 3
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Verrikan Nexus]
+//
+//
+//  go run main.go 1 2
+//    ["Normandy" "Verrikan" "Nexus" "Warsaw"]
+//
+//    [Verrikan]
+//
+// ---------------------------------------------------------
+
+func main() {
+	// uncomment the slice below
+	// ships := []string{"Normandy", "Verrikan", "Nexus", "Warsaw"}
+}