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course/4-structs/exercises/2-nested_structs/code.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"fmt"
+)
+
+type messageToSend struct {
+	message   string
+	sender    user
+	recipient user
+}
+
+type user struct {
+	name   string
+	number int
+}
+
+func canSendMessage(mToSend messageToSend) bool {
+	// ?
+	return true
+}
+
+// don't touch below this line
+
+func test(mToSend messageToSend) {
+	fmt.Printf(`sending "%s" from %s (%v) to %s (%v)...`,
+		mToSend.message,
+		mToSend.sender.name,
+		mToSend.sender.number,
+		mToSend.recipient.name,
+		mToSend.recipient.number,
+	)
+	fmt.Println()
+	if canSendMessage(mToSend) {
+		fmt.Println("...sent!")
+	} else {
+		fmt.Println("...can't send message")
+	}
+	fmt.Println("====================================")
+}
+
+func main() {
+	test(messageToSend{
+		message: "you have an appointment tommorow",
+		sender: user{
+			name:   "Brenda Halafax",
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Sally Sue",
+			number: 19035558973,
+		},
+	})
+	test(messageToSend{
+		message: "you have an event tommorow",
+		sender: user{
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Suzie Sall",
+			number: 0,
+		},
+	})
+	test(messageToSend{
+		message: "you have an party tommorow",
+		sender: user{
+			name:   "Njorn Halafax",
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Sally Sue",
+			number: 19035558973,
+		},
+	})
+	test(messageToSend{
+		message: "you have a birthday tommorow",
+		sender: user{
+			name:   "Eli Halafax",
+			number: 0,
+		},
+		recipient: user{
+			name:   "Whitaker Sue",
+			number: 19035558973,
+		},
+	})
+}

course/4-structs/exercises/2-nested_structs/complete.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"fmt"
+)
+
+type messageToSend struct {
+	message   string
+	sender    user
+	recipient user
+}
+
+type user struct {
+	name   string
+	number int
+}
+
+func canSendMessage(mToSend messageToSend) bool {
+	if mToSend.recipient.number == 0 {
+		return false
+	}
+	if mToSend.sender.number == 0 {
+		return false
+	}
+	if mToSend.recipient.name == "" {
+		return false
+	}
+	if mToSend.sender.name == "" {
+		return false
+	}
+	return true
+}
+
+// don't touch below this line
+
+func test(mToSend messageToSend) {
+	fmt.Printf(`sending "%s" from %s (%v) to %s (%v)...`,
+		mToSend.message,
+		mToSend.sender.name,
+		mToSend.sender.number,
+		mToSend.recipient.name,
+		mToSend.recipient.number,
+	)
+	fmt.Println()
+	if canSendMessage(mToSend) {
+		fmt.Println("...sent!")
+	} else {
+		fmt.Println("...can't send message")
+	}
+	fmt.Println("====================================")
+}
+
+func main() {
+	test(messageToSend{
+		message: "you have an appointment tommorow",
+		sender: user{
+			name:   "Brenda Halafax",
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Sally Sue",
+			number: 19035558973,
+		},
+	})
+	test(messageToSend{
+		message: "you have an event tommorow",
+		sender: user{
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Suzie Sall",
+			number: 0,
+		},
+	})
+	test(messageToSend{
+		message: "you have an party tommorow",
+		sender: user{
+			name:   "Njorn Halafax",
+			number: 16545550987,
+		},
+		recipient: user{
+			name:   "Sally Sue",
+			number: 19035558973,
+		},
+	})
+	test(messageToSend{
+		message: "you have a birthday tommorow",
+		sender: user{
+			name:   "Eli Halafax",
+			number: 0,
+		},
+		recipient: user{
+			name:   "Whitaker Sue",
+			number: 19035558973,
+		},
+	})
+}

course/4-structs/exercises/2-nested_structs/expected.txt

@@ -0,0 +1,12 @@
+sending "you have an appointment tommorow" from Brenda Halafax (16545550987) to Sally Sue (19035558973)...
+...sent!
+====================================
+sending "you have an event tommorow" from  (16545550987) to Suzie Sall (0)...
+...can't send message
+====================================
+sending "you have an party tommorow" from Njorn Halafax (16545550987) to Sally Sue (19035558973)...
+...sent!
+====================================
+sending "you have a birthday tommorow" from Eli Halafax (0) to Whitaker Sue (19035558973)...
+...can't send message
+====================================

course/4-structs/exercises/2-nested_structs/readme.md

@@ -0,0 +1,34 @@
+# Nested structs in Go
+
+Structs can be nested to represent more complex entities:
+
+```go
+type car struct {
+  Make string
+  Model string
+  Height int
+  Width int
+  FrontWheel Wheel
+  BackWheel Wheel
+}
+
+type Wheel struct {
+  Radius int
+  Material string
+}
+```
+
+The fields of a struct can be accessed using the dot `.` operator.
+
+```go
+myCar := car{}
+myCar.FrontWheel.Radius = 5
+```
+
+## Assignment
+
+Textio has a bug, we've been sending texts with information missing! Before we send text messages in Textio, we should check to make sure the required fields have non-zero values.
+
+Notice that the `user` struct is a nested struct within the `messageToSend` struct. Both `sender` and `recipient` are `user` struct types.
+
+Complete the `canSendMessage` function. It should return `true` only if the `sender` and `recipient` fields each contain a `name` and a `number`. If any of the default zero values are present, return `false` instead.