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diff --git a/src/fmt/example_test.go b/src/fmt/example_test.go
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+// Copyright 2017 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"
+	"io"
+	"math"
+	"os"
+	"strings"
+	"time"
+)
+
+// The Errorf function lets us use formatting features
+// to create descriptive error messages.
+func ExampleErrorf() {
+	const name, id = "bueller", 17
+	err := fmt.Errorf("user %q (id %d) not found", name, id)
+	fmt.Println(err.Error())
+
+	// Output: user "bueller" (id 17) not found
+}
+
+func ExampleFscanf() {
+	var (
+		i int
+		b bool
+		s string
+	)
+	r := strings.NewReader("5 true gophers")
+	n, err := fmt.Fscanf(r, "%d %t %s", &i, &b, &s)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Fscanf: %v\n", err)
+	}
+	fmt.Println(i, b, s)
+	fmt.Println(n)
+	// Output:
+	// 5 true gophers
+	// 3
+}
+
+func ExampleFscanln() {
+	s := `dmr 1771 1.61803398875
+	ken 271828 3.14159`
+	r := strings.NewReader(s)
+	var a string
+	var b int
+	var c float64
+	for {
+		n, err := fmt.Fscanln(r, &a, &b, &c)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			panic(err)
+		}
+		fmt.Printf("%d: %s, %d, %f\n", n, a, b, c)
+	}
+	// Output:
+	// 3: dmr, 1771, 1.618034
+	// 3: ken, 271828, 3.141590
+}
+
+func ExampleSscanf() {
+	var name string
+	var age int
+	n, err := fmt.Sscanf("Kim is 22 years old", "%s is %d years old", &name, &age)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("%d: %s, %d\n", n, name, age)
+
+	// Output:
+	// 2: Kim, 22
+}
+
+func ExamplePrint() {
+	const name, age = "Kim", 22
+	fmt.Print(name, " is ", age, " years old.\n")
+
+	// It is conventional not to worry about any
+	// error returned by Print.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExamplePrintln() {
+	const name, age = "Kim", 22
+	fmt.Println(name, "is", age, "years old.")
+
+	// It is conventional not to worry about any
+	// error returned by Println.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExamplePrintf() {
+	const name, age = "Kim", 22
+	fmt.Printf("%s is %d years old.\n", name, age)
+
+	// It is conventional not to worry about any
+	// error returned by Printf.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExampleSprint() {
+	const name, age = "Kim", 22
+	s := fmt.Sprint(name, " is ", age, " years old.\n")
+
+	io.WriteString(os.Stdout, s) // Ignoring error for simplicity.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExampleSprintln() {
+	const name, age = "Kim", 22
+	s := fmt.Sprintln(name, "is", age, "years old.")
+
+	io.WriteString(os.Stdout, s) // Ignoring error for simplicity.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExampleSprintf() {
+	const name, age = "Kim", 22
+	s := fmt.Sprintf("%s is %d years old.\n", name, age)
+
+	io.WriteString(os.Stdout, s) // Ignoring error for simplicity.
+
+	// Output:
+	// Kim is 22 years old.
+}
+
+func ExampleFprint() {
+	const name, age = "Kim", 22
+	n, err := fmt.Fprint(os.Stdout, name, " is ", age, " years old.\n")
+
+	// The n and err return values from Fprint are
+	// those returned by the underlying io.Writer.
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Fprint: %v\n", err)
+	}
+	fmt.Print(n, " bytes written.\n")
+
+	// Output:
+	// Kim is 22 years old.
+	// 21 bytes written.
+}
+
+func ExampleFprintln() {
+	const name, age = "Kim", 22
+	n, err := fmt.Fprintln(os.Stdout, name, "is", age, "years old.")
+
+	// The n and err return values from Fprintln are
+	// those returned by the underlying io.Writer.
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Fprintln: %v\n", err)
+	}
+	fmt.Println(n, "bytes written.")
+
+	// Output:
+	// Kim is 22 years old.
+	// 21 bytes written.
+}
+
+func ExampleFprintf() {
+	const name, age = "Kim", 22
+	n, err := fmt.Fprintf(os.Stdout, "%s is %d years old.\n", name, age)
+
+	// The n and err return values from Fprintf are
+	// those returned by the underlying io.Writer.
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Fprintf: %v\n", err)
+	}
+	fmt.Printf("%d bytes written.\n", n)
+
+	// Output:
+	// Kim is 22 years old.
+	// 21 bytes written.
+}
+
+// Print, Println, and Printf lay out their arguments differently. In this example
+// we can compare their behaviors. Println always adds blanks between the items it
+// prints, while Print adds blanks only between non-string arguments and Printf
+// does exactly what it is told.
+// Sprint, Sprintln, Sprintf, Fprint, Fprintln, and Fprintf behave the same as
+// their corresponding Print, Println, and Printf functions shown here.
+func Example_printers() {
+	a, b := 3.0, 4.0
+	h := math.Hypot(a, b)
+
+	// Print inserts blanks between arguments when neither is a string.
+	// It does not add a newline to the output, so we add one explicitly.
+	fmt.Print("The vector (", a, b, ") has length ", h, ".\n")
+
+	// Println always inserts spaces between its arguments,
+	// so it cannot be used to produce the same output as Print in this case;
+	// its output has extra spaces.
+	// Also, Println always adds a newline to the output.
+	fmt.Println("The vector (", a, b, ") has length", h, ".")
+
+	// Printf provides complete control but is more complex to use.
+	// It does not add a newline to the output, so we add one explicitly
+	// at the end of the format specifier string.
+	fmt.Printf("The vector (%g %g) has length %g.\n", a, b, h)
+
+	// Output:
+	// The vector (3 4) has length 5.
+	// The vector ( 3 4 ) has length 5 .
+	// The vector (3 4) has length 5.
+}
+
+// These examples demonstrate the basics of printing using a format string. Printf,
+// Sprintf, and Fprintf all take a format string that specifies how to format the
+// subsequent arguments. For example, %d (we call that a 'verb') says to print the
+// corresponding argument, which must be an integer (or something containing an
+// integer, such as a slice of ints) in decimal. The verb %v ('v' for 'value')
+// always formats the argument in its default form, just how Print or Println would
+// show it. The special verb %T ('T' for 'Type') prints the type of the argument
+// rather than its value. The examples are not exhaustive; see the package comment
+// for all the details.
+func Example_formats() {
+	// A basic set of examples showing that %v is the default format, in this
+	// case decimal for integers, which can be explicitly requested with %d;
+	// the output is just what Println generates.
+	integer := 23
+	// Each of these prints "23" (without the quotes).
+	fmt.Println(integer)
+	fmt.Printf("%v\n", integer)
+	fmt.Printf("%d\n", integer)
+
+	// The special verb %T shows the type of an item rather than its value.
+	fmt.Printf("%T %T\n", integer, &integer)
+	// Result: int *int
+
+	// Println(x) is the same as Printf("%v\n", x) so we will use only Printf
+	// in the following examples. Each one demonstrates how to format values of
+	// a particular type, such as integers or strings. We start each format
+	// string with %v to show the default output and follow that with one or
+	// more custom formats.
+
+	// Booleans print as "true" or "false" with %v or %t.
+	truth := true
+	fmt.Printf("%v %t\n", truth, truth)
+	// Result: true true
+
+	// Integers print as decimals with %v and %d,
+	// or in hex with %x, octal with %o, or binary with %b.
+	answer := 42
+	fmt.Printf("%v %d %x %o %b\n", answer, answer, answer, answer, answer)
+	// Result: 42 42 2a 52 101010
+
+	// Floats have multiple formats: %v and %g print a compact representation,
+	// while %f prints a decimal point and %e uses exponential notation. The
+	// format %6.2f used here shows how to set the width and precision to
+	// control the appearance of a floating-point value. In this instance, 6 is
+	// the total width of the printed text for the value (note the extra spaces
+	// in the output) and 2 is the number of decimal places to show.
+	pi := math.Pi
+	fmt.Printf("%v %g %.2f (%6.2f) %e\n", pi, pi, pi, pi, pi)
+	// Result: 3.141592653589793 3.141592653589793 3.14 (  3.14) 3.141593e+00
+
+	// Complex numbers format as parenthesized pairs of floats, with an 'i'
+	// after the imaginary part.
+	point := 110.7 + 22.5i
+	fmt.Printf("%v %g %.2f %.2e\n", point, point, point, point)
+	// Result: (110.7+22.5i) (110.7+22.5i) (110.70+22.50i) (1.11e+02+2.25e+01i)
+
+	// Runes are integers but when printed with %c show the character with that
+	// Unicode value. The %q verb shows them as quoted characters, %U as a
+	// hex Unicode code point, and %#U as both a code point and a quoted
+	// printable form if the rune is printable.
+	smile := '😀'
+	fmt.Printf("%v %d %c %q %U %#U\n", smile, smile, smile, smile, smile, smile)
+	// Result: 128512 128512 😀 '😀' U+1F600 U+1F600 '😀'
+
+	// Strings are formatted with %v and %s as-is, with %q as quoted strings,
+	// and %#q as backquoted strings.
+	placeholders := `foo "bar"`
+	fmt.Printf("%v %s %q %#q\n", placeholders, placeholders, placeholders, placeholders)
+	// Result: foo "bar" foo "bar" "foo \"bar\"" `foo "bar"`
+
+	// Maps formatted with %v show keys and values in their default formats.
+	// The %#v form (the # is called a "flag" in this context) shows the map in
+	// the Go source format. Maps are printed in a consistent order, sorted
+	// by the values of the keys.
+	isLegume := map[string]bool{
+		"peanut":    true,
+		"dachshund": false,
+	}
+	fmt.Printf("%v %#v\n", isLegume, isLegume)
+	// Result: map[dachshund:false peanut:true] map[string]bool{"dachshund":false, "peanut":true}
+
+	// Structs formatted with %v show field values in their default formats.
+	// The %+v form shows the fields by name, while %#v formats the struct in
+	// Go source format.
+	person := struct {
+		Name string
+		Age  int
+	}{"Kim", 22}
+	fmt.Printf("%v %+v %#v\n", person, person, person)
+	// Result: {Kim 22} {Name:Kim Age:22} struct { Name string; Age int }{Name:"Kim", Age:22}
+
+	// The default format for a pointer shows the underlying value preceded by
+	// an ampersand. The %p verb prints the pointer value in hex. We use a
+	// typed nil for the argument to %p here because the value of any non-nil
+	// pointer would change from run to run; run the commented-out Printf
+	// call yourself to see.
+	pointer := &person
+	fmt.Printf("%v %p\n", pointer, (*int)(nil))
+	// Result: &{Kim 22} 0x0
+	// fmt.Printf("%v %p\n", pointer, pointer)
+	// Result: &{Kim 22} 0x010203 // See comment above.
+
+	// Arrays and slices are formatted by applying the format to each element.
+	greats := [5]string{"Kitano", "Kobayashi", "Kurosawa", "Miyazaki", "Ozu"}
+	fmt.Printf("%v %q\n", greats, greats)
+	// Result: [Kitano Kobayashi Kurosawa Miyazaki Ozu] ["Kitano" "Kobayashi" "Kurosawa" "Miyazaki" "Ozu"]
+
+	kGreats := greats[:3]
+	fmt.Printf("%v %q %#v\n", kGreats, kGreats, kGreats)
+	// Result: [Kitano Kobayashi Kurosawa] ["Kitano" "Kobayashi" "Kurosawa"] []string{"Kitano", "Kobayashi", "Kurosawa"}
+
+	// Byte slices are special. Integer verbs like %d print the elements in
+	// that format. The %s and %q forms treat the slice like a string. The %x
+	// verb has a special form with the space flag that puts a space between
+	// the bytes.
+	cmd := []byte("a⌘")
+	fmt.Printf("%v %d %s %q %x % x\n", cmd, cmd, cmd, cmd, cmd, cmd)
+	// Result: [97 226 140 152] [97 226 140 152] a⌘ "a⌘" 61e28c98 61 e2 8c 98
+
+	// Types that implement Stringer are printed the same as strings. Because
+	// Stringers return a string, we can print them using a string-specific
+	// verb such as %q.
+	now := time.Unix(123456789, 0).UTC() // time.Time implements fmt.Stringer.
+	fmt.Printf("%v %q\n", now, now)
+	// Result: 1973-11-29 21:33:09 +0000 UTC "1973-11-29 21:33:09 +0000 UTC"
+
+	// Output:
+	// 23
+	// 23
+	// 23
+	// int *int
+	// true true
+	// 42 42 2a 52 101010
+	// 3.141592653589793 3.141592653589793 3.14 (  3.14) 3.141593e+00
+	// (110.7+22.5i) (110.7+22.5i) (110.70+22.50i) (1.11e+02+2.25e+01i)
+	// 128512 128512 😀 '😀' U+1F600 U+1F600 '😀'
+	// foo "bar" foo "bar" "foo \"bar\"" `foo "bar"`
+	// map[dachshund:false peanut:true] map[string]bool{"dachshund":false, "peanut":true}
+	// {Kim 22} {Name:Kim Age:22} struct { Name string; Age int }{Name:"Kim", Age:22}
+	// &{Kim 22} 0x0
+	// [Kitano Kobayashi Kurosawa Miyazaki Ozu] ["Kitano" "Kobayashi" "Kurosawa" "Miyazaki" "Ozu"]
+	// [Kitano Kobayashi Kurosawa] ["Kitano" "Kobayashi" "Kurosawa"] []string{"Kitano", "Kobayashi", "Kurosawa"}
+	// [97 226 140 152] [97 226 140 152] a⌘ "a⌘" 61e28c98 61 e2 8c 98
+	// 1973-11-29 21:33:09 +0000 UTC "1973-11-29 21:33:09 +0000 UTC"
+}