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// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package fmt_test
import (
"fmt"
)
// Address has a City, State and a Country.
type Address struct {
City string
State string
Country string
}
// Person has a Name, Age and Address.
type Person struct {
Name string
Age uint
Addr *Address
}
// GoString makes Person satisfy the GoStringer interface.
// The return value is valid Go code that can be used to reproduce the Person struct.
func (p Person) GoString() string {
if p.Addr != nil {
return fmt.Sprintf("Person{Name: %q, Age: %d, Addr: &Address{City: %q, State: %q, Country: %q}}", p.Name, int(p.Age), p.Addr.City, p.Addr.State, p.Addr.Country)
}
return fmt.Sprintf("Person{Name: %q, Age: %d}", p.Name, int(p.Age))
}
func ExampleGoStringer() {
p1 := Person{
Name: "Warren",
Age: 31,
Addr: &Address{
City: "Denver",
State: "CO",
Country: "U.S.A.",
},
}
// If GoString() wasn't implemented, the output of `fmt.Printf("%#v", p1)` would be similar to
// Person{Name:"Warren", Age:0x1f, Addr:(*main.Address)(0x10448240)}
fmt.Printf("%#v\n", p1)
p2 := Person{
Name: "Theia",
Age: 4,
}
// If GoString() wasn't implemented, the output of `fmt.Printf("%#v", p2)` would be similar to
// Person{Name:"Theia", Age:0x4, Addr:(*main.Address)(nil)}
fmt.Printf("%#v\n", p2)
// Output:
// Person{Name: "Warren", Age: 31, Addr: &Address{City: "Denver", State: "CO", Country: "U.S.A."}}
// Person{Name: "Theia", Age: 4}
}
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