// Copyright 2011 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 bytes_test
import (
"bytes"
"encoding/base64"
"fmt"
"io"
"os"
"sort"
"unicode"
)
func ExampleBuffer() {
var b bytes.Buffer // A Buffer needs no initialization.
b.Write([]byte("Hello "))
fmt.Fprintf(&b, "world!")
b.WriteTo(os.Stdout)
// Output: Hello world!
}
func ExampleBuffer_reader() {
// A Buffer can turn a string or a []byte into an io.Reader.
buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
dec := base64.NewDecoder(base64.StdEncoding, buf)
io.Copy(os.Stdout, dec)
// Output: Gophers rule!
}
func ExampleCompare() {
// Interpret Compare's result by comparing it to zero.
var a, b []byte
if bytes.Compare(a, b) < 0 {
// a less b
}
if bytes.Compare(a, b) <= 0 {
// a less or equal b
}
if bytes.Compare(a, b) > 0 {
// a greater b
}
if bytes.Compare(a, b) >= 0 {
// a greater or equal b
}
// Prefer Equal to Compare for equality comparisons.
if bytes.Equal(a, b) {
// a equal b
}
if !bytes.Equal(a, b) {
// a not equal b
}
}
func ExampleCompare_search() {
// Binary search to find a matching byte slice.
var needle []byte
var haystack [][]byte // Assume sorted
i := sort.Search(len(haystack), func(i int) bool {
// Return haystack[i] >= needle.
return bytes.Compare(haystack[i], needle) >= 0
})
if i < len(haystack) && bytes.Equal(haystack[i], needle) {
// Found it!
}
}
func ExampleTrimSuffix() {
var b = []byte("Hello, goodbye, etc!")
b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
b = bytes.TrimSuffix(b, []byte("gopher"))
b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
os.Stdout.Write(b)
// Output: Hello, world!
}
func ExampleTrimPrefix() {
var b = []byte("Goodbye,, world!")
b = bytes.TrimPrefix(b, []byte("Goodbye,"))
b = bytes.TrimPrefix(b, []byte("See ya,"))
fmt.Printf("Hello%s", b)
// Output: Hello, world!
}
func ExampleFields() {
fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz ")))
// Output: Fields are: ["foo" "bar" "baz"]
}
func ExampleFieldsFunc() {
f := func(c rune) bool {
return !unicode.IsLetter(c) && !unicode.IsNumber(c)
}
fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte(" foo1;bar2,baz3..."), f))
// Output: Fields are: ["foo1" "bar2" "baz3"]
}
func ExampleContains() {
fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("")))
fmt.Println(bytes.Contains([]byte(""), []byte("")))
// Output:
// true
// false
// true
// true
}
func ExampleCount() {
fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
// Output:
// 3
// 5
}
func ExampleEqualFold() {
fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
// Output: true
}
func ExampleHasPrefix() {
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("")))
// Output:
// true
// false
// true
}
func ExampleHasSuffix() {
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("go")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("O")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("Ami")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("")))
// Output:
// true
// false
// false
// true
}
func ExampleIndex() {
fmt.Println(bytes.Index([]byte("chicken"), []byte("ken")))
fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr")))
// Output:
// 4
// -1
}
func ExampleIndexFunc() {
f := func(c rune) bool {
return unicode.Is(unicode.Han, c)
}
fmt.Println(bytes.IndexFunc([]byte("Hello, 世界"), f))
fmt.Println(bytes.IndexFunc([]byte("Hello, world"), f))
// Output:
// 7
// -1
}
func ExampleIndexAny() {
fmt.Println(bytes.IndexAny([]byte("chicken"), "aeiouy"))
fmt.Println(bytes.IndexAny([]byte("crwth"), "aeiouy"))
// Output:
// 2
// -1
}
func ExampleIndexRune() {
fmt.Println(bytes.IndexRune([]byte("chicken"), 'k'))
fmt.Println(bytes.IndexRune([]byte("chicken"), 'd'))
// Output:
// 4
// -1
}
func ExampleLastIndex() {
fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("rodent")))
// Output:
// 0
// 3
// -1
}
func ExampleJoin() {
s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
fmt.Printf("%s", bytes.Join(s, []byte(", ")))
// Output: foo, bar, baz
}
func ExampleRepeat() {
fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
// Output: banana
}
func ExampleReplace() {
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("k"), []byte("ky"), 2))
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("oink"), []byte("moo"), -1))
// Output:
// oinky oinky oink
// moo moo moo
}
func ExampleSplit() {
fmt.Printf("%q\n", bytes.Split([]byte("a,b,c"), []byte(",")))
fmt.Printf("%q\n", bytes.Split([]byte("a man a plan a canal panama"), []byte("a ")))
fmt.Printf("%q\n", bytes.Split([]byte(" xyz "), []byte("")))
fmt.Printf("%q\n", bytes.Split([]byte(""), []byte("Bernardo O'Higgins")))
// Output:
// ["a" "b" "c"]
// ["" "man " "plan " "canal panama"]
// [" " "x" "y" "z" " "]
// [""]
}
func ExampleSplitN() {
fmt.Printf("%q\n", bytes.SplitN([]byte("a,b,c"), []byte(","), 2))
z := bytes.SplitN([]byte("a,b,c"), []byte(","), 0)
fmt.Printf("%q (nil = %v)\n", z, z == nil)
// Output:
// ["a" "b,c"]
// [] (nil = true)
}
func ExampleSplitAfter() {
fmt.Printf("%q\n", bytes.SplitAfter([]byte("a,b,c"), []byte(",")))
// Output: ["a," "b," "c"]
}
func ExampleSplitAfterN() {
fmt.Printf("%q\n", bytes.SplitAfterN([]byte("a,b,c"), []byte(","), 2))
// Output: ["a," "b,c"]
}
func ExampleTitle() {
fmt.Printf("%s", bytes.Title([]byte("her royal highness")))
// Output: Her Royal Highness
}
func ExampleToTitle() {
fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises")))
fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб")))
// Output:
// LOUD NOISES
// ХЛЕБ
}
func ExampleTrim() {
fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
// Output: ["Achtung! Achtung"]
}
func ExampleMap() {
rot13 := func(r rune) rune {
switch {
case r >= 'A' && r <= 'Z':
return 'A' + (r-'A'+13)%26
case r >= 'a' && r <= 'z':
return 'a' + (r-'a'+13)%26
}
return r
}
fmt.Printf("%s", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
}
func ExampleTrimSpace() {
fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
// Output: a lone gopher
}
func ExampleToUpper() {
fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
// Output: GOPHER
}
func ExampleToLower() {
fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
// Output: gopher
}