31 lines
827 B
Go
31 lines
827 B
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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package main
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import (
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"fmt"
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)
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type book struct {
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product
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published timestamp
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}
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// String method makes the book an fmt.Stringer.
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// The list was calling the embedded product type's String(),
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// now it calls the book.String().
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func (b *book) String() string {
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// product.String() has a pointer receiver.
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// Therefore, you need to manually take the product's address.
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//
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// If you pass: "b.product", Go would pass it as a copy to `Sprintf`.
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// In that case, Go can't deference b.product automatically.
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// It's because: b.product would be a different value, a copy.
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return fmt.Sprintf("%s - (%s)", &b.product, b.published)
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}
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