// 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 ( "strings" ) type list []*product func (l list) String() string { if len(l) == 0 { return "Sorry. We're waiting for delivery 🚚.\n" } var str strings.Builder for _, p := range l { // fmt.Printf("* %s\n", p) str.WriteString("* ") str.WriteString(p.String()) str.WriteRune('\n') } return str.String() } func (l list) discount(ratio float64) { for _, p := range l { p.discount(ratio) } }