add: map exercises and quiz

22-maps/exercises/02-populate/main.go

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+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Populate and Lookup
+//
+//  Add elements to the maps that you've declared in the
+//  first exercise, and try them by looking up for the keys.
+//
+//  Use map literals.
+//
+//  After completing the exercise, remove the data and check
+//  that your program still works.
+//
+//
+//  1. Phone numbers by last name
+//     --------------------------
+//     bowen  202-555-0179
+//     dulin  03.37.77.63.06
+//     greco  03489940240
+//
+//     Print the dulin's phone number.
+//
+//
+//  2. Product availability by Product ID
+//     ----------------
+//     617841573 true
+//     879401371 false
+//     576872813 true
+//
+//     Is Product ID 879401371 available?
+//
+//
+//  3. Multiple phone numbers by last name
+//     ------------------------------------------------------
+//     bowen  [202-555-0179]
+//     dulin  [03.37.77.63.06 03.37.70.50.05 02.20.40.10.04]
+//     greco  [03489940240 03489900120]
+//
+//     What is Greco's second phone number?
+//
+//
+//  4. Shopping basket by Customer ID
+//     -------------------------------
+//     100 [617841573:4 576872813:2]
+//     101 [576872813:5 657473833:20]
+//     102 []
+//
+//     How many of 576872813 the customer 101 is going to buy?
+//                (Product ID)  (Customer ID)
+//
+//
+// EXPECTED OUTPUT
+//
+//   1. Run the solution to see the output
+//   2. Here is the output with empty maps:
+//
+//      dulin's phone number: N/A
+//      Product ID #879401371 is not available
+//      greco's 2nd phone number: N/A
+//      Customer #101 is going to buy 0 from Product ID #576872813.
+//
+// ---------------------------------------------------------
+
+func main() {
+}

22-maps/exercises/02-populate/solution/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	phones := map[string]string{
+		"bowen": "202-555-0179",
+		"dulin": "03.37.77.63.06",
+		"greco": "03489940240",
+	}
+
+	products := map[int]bool{
+		617841573: true,
+		879401371: false,
+		576872813: true,
+	}
+
+	multiPhones := map[string][]string{
+		"bowen": []string{"202-555-0179"},
+		"dulin": []string{
+			"03.37.77.63.06", "03.37.70.50.05", "02.20.40.10.04",
+		},
+		"greco": []string{"03489940240", "03489900120"},
+	}
+
+	basket := map[int]map[int]int{
+		100: {617841573: 4, 576872813: 2},
+		101: {576872813: 5, 657473833: 20},
+		102: {},
+	}
+
+	// Print dulin's phone number.
+	who, phone := "dulin", "N/A"
+	if v, ok := phones[who]; ok {
+		phone = v
+	}
+	fmt.Printf("%s's phone number: %s\n", who, phone)
+
+	// Is Product ID 879401371 available?
+	id, status := 879401371, "available"
+	if !products[id] {
+		status = "not " + status
+	}
+	fmt.Printf("Product ID #%d is %s\n", id, status)
+
+	// What is Greco's second phone number?
+	who, phone = "greco", "N/A"
+	if phones := multiPhones[who]; len(phones) >= 2 {
+		phone = phones[1]
+	}
+	fmt.Printf("%s's 2nd phone number: %s\n", who, phone)
+
+	// How many of 576872813 the customer 101 is going to buy?
+	cid, pid := 101, 576872813
+	fmt.Printf("Customer #%d is going to buy %d from Product ID #%d.\n", cid, basket[cid][pid], pid)
+}