Initial commit

07-printf/04-coding/main.go

@@ -0,0 +1,51 @@
+// 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() {
+	var (
+		planet   = "venus"
+		distance = 261
+		orbital  = 224.701
+		hasLife  = false
+	)
+
+	// swiss army knife %v verb
+	fmt.Printf("Planet: %v\n", planet)
+	fmt.Printf("Distance: %v millions kms\n", distance)
+	fmt.Printf("Orbital Period: %v days\n", orbital)
+	fmt.Printf("Does %v have life? %v\n", planet, hasLife)
+
+	// argument indexing - indexes start from 1
+	fmt.Printf(
+		"%v is %v away. Think! %[2]v kms! %[1]v OMG.\n",
+		planet, distance,
+	)
+
+	// why use other verbs than? because: type-safety
+	// uncomment to see the warnings:
+	//
+	// fmt.Printf("Planet: %d\n", planet)
+	// fmt.Printf("Distance: %s millions kms\n", distance)
+	// fmt.Printf("Orbital Period: %t days\n", orbital)
+	// fmt.Printf("Does %v has life? %f\n", planet, hasLife)
+
+	// correct verbs:
+	// fmt.Printf("Planet: %s\n", planet)
+	// fmt.Printf("Distance: %d millions kms\n", distance)
+	// fmt.Printf("Orbital Period: %f days\n", orbital)
+	// fmt.Printf("Does %s has life? %t\n", planet, hasLife)
+
+	// precision
+	fmt.Printf("Orbital Period: %f days\n", orbital)
+	fmt.Printf("Orbital Period: %.0f days\n", orbital)
+	fmt.Printf("Orbital Period: %.1f days\n", orbital)
+	fmt.Printf("Orbital Period: %.2f days\n", orbital)
+}