golang/src/strings/example_test.go

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// Copyright 2012 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 strings_test
import (
"fmt"
"strings"
"unicode"
"unsafe"
)
func ExampleClone() {
s := "abc"
clone := strings.Clone(s)
fmt.Println(s == clone)
fmt.Println(unsafe.StringData(s) == unsafe.StringData(clone))
// Output:
// true
// false
}
func ExampleBuilder() {
var b strings.Builder
for i := 3; i >= 1; i-- {
fmt.Fprintf(&b, "%d...", i)
}
b.WriteString("ignition")
fmt.Println(b.String())
// Output: 3...2...1...ignition
}
func ExampleCompare() {
fmt.Println(strings.Compare("a", "b"))
fmt.Println(strings.Compare("a", "a"))
fmt.Println(strings.Compare("b", "a"))
// Output:
// -1
// 0
// 1
}
func ExampleContains() {
fmt.Println(strings.Contains("seafood", "foo"))
fmt.Println(strings.Contains("seafood", "bar"))
fmt.Println(strings.Contains("seafood", ""))
fmt.Println(strings.Contains("", ""))
// Output:
// true
// false
// true
// true
}
func ExampleContainsAny() {
fmt.Println(strings.ContainsAny("team", "i"))
fmt.Println(strings.ContainsAny("fail", "ui"))
fmt.Println(strings.ContainsAny("ure", "ui"))
fmt.Println(strings.ContainsAny("failure", "ui"))
fmt.Println(strings.ContainsAny("foo", ""))
fmt.Println(strings.ContainsAny("", ""))
// Output:
// false
// true
// true
// true
// false
// false
}
func ExampleContainsRune() {
// Finds whether a string contains a particular Unicode code point.
// The code point for the lowercase letter "a", for example, is 97.
fmt.Println(strings.ContainsRune("aardvark", 97))
fmt.Println(strings.ContainsRune("timeout", 97))
// Output:
// true
// false
}
func ExampleContainsFunc() {
f := func(r rune) bool {
return r == 'a' || r == 'e' || r == 'i' || r == 'o' || r == 'u'
}
fmt.Println(strings.ContainsFunc("hello", f))
fmt.Println(strings.ContainsFunc("rhythms", f))
// Output:
// true
// false
}
func ExampleCount() {
fmt.Println(strings.Count("cheese", "e"))
fmt.Println(strings.Count("five", "")) // before & after each rune
// Output:
// 3
// 5
}
func ExampleCut() {
show := func(s, sep string) {
before, after, found := strings.Cut(s, sep)
fmt.Printf("Cut(%q, %q) = %q, %q, %v\n", s, sep, before, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
show("Gopher", "er")
show("Gopher", "Badger")
// Output:
// Cut("Gopher", "Go") = "", "pher", true
// Cut("Gopher", "ph") = "Go", "er", true
// Cut("Gopher", "er") = "Goph", "", true
// Cut("Gopher", "Badger") = "Gopher", "", false
}
func ExampleCutPrefix() {
show := func(s, sep string) {
after, found := strings.CutPrefix(s, sep)
fmt.Printf("CutPrefix(%q, %q) = %q, %v\n", s, sep, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
// Output:
// CutPrefix("Gopher", "Go") = "pher", true
// CutPrefix("Gopher", "ph") = "Gopher", false
}
func ExampleCutSuffix() {
show := func(s, sep string) {
before, found := strings.CutSuffix(s, sep)
fmt.Printf("CutSuffix(%q, %q) = %q, %v\n", s, sep, before, found)
}
show("Gopher", "Go")
show("Gopher", "er")
// Output:
// CutSuffix("Gopher", "Go") = "Gopher", false
// CutSuffix("Gopher", "er") = "Goph", true
}
func ExampleEqualFold() {
fmt.Println(strings.EqualFold("Go", "go"))
fmt.Println(strings.EqualFold("AB", "ab")) // true because comparison uses simple case-folding
fmt.Println(strings.EqualFold("ß", "ss")) // false because comparison does not use full case-folding
// Output:
// true
// true
// false
}
func ExampleFields() {
fmt.Printf("Fields are: %q", strings.Fields(" 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", strings.FieldsFunc(" foo1;bar2,baz3...", f))
// Output: Fields are: ["foo1" "bar2" "baz3"]
}
func ExampleHasPrefix() {
fmt.Println(strings.HasPrefix("Gopher", "Go"))
fmt.Println(strings.HasPrefix("Gopher", "C"))
fmt.Println(strings.HasPrefix("Gopher", ""))
// Output:
// true
// false
// true
}
func ExampleHasSuffix() {
fmt.Println(strings.HasSuffix("Amigo", "go"))
fmt.Println(strings.HasSuffix("Amigo", "O"))
fmt.Println(strings.HasSuffix("Amigo", "Ami"))
fmt.Println(strings.HasSuffix("Amigo", ""))
// Output:
// true
// false
// false
// true
}
func ExampleIndex() {
fmt.Println(strings.Index("chicken", "ken"))
fmt.Println(strings.Index("chicken", "dmr"))
// Output:
// 4
// -1
}
func ExampleIndexFunc() {
f := func(c rune) bool {
return unicode.Is(unicode.Han, c)
}
fmt.Println(strings.IndexFunc("Hello, 世界", f))
fmt.Println(strings.IndexFunc("Hello, world", f))
// Output:
// 7
// -1
}
func ExampleIndexAny() {
fmt.Println(strings.IndexAny("chicken", "aeiouy"))
fmt.Println(strings.IndexAny("crwth", "aeiouy"))
// Output:
// 2
// -1
}
func ExampleIndexByte() {
fmt.Println(strings.IndexByte("golang", 'g'))
fmt.Println(strings.IndexByte("gophers", 'h'))
fmt.Println(strings.IndexByte("golang", 'x'))
// Output:
// 0
// 3
// -1
}
func ExampleIndexRune() {
fmt.Println(strings.IndexRune("chicken", 'k'))
fmt.Println(strings.IndexRune("chicken", 'd'))
// Output:
// 4
// -1
}
func ExampleLastIndex() {
fmt.Println(strings.Index("go gopher", "go"))
fmt.Println(strings.LastIndex("go gopher", "go"))
fmt.Println(strings.LastIndex("go gopher", "rodent"))
// Output:
// 0
// 3
// -1
}
func ExampleLastIndexAny() {
fmt.Println(strings.LastIndexAny("go gopher", "go"))
fmt.Println(strings.LastIndexAny("go gopher", "rodent"))
fmt.Println(strings.LastIndexAny("go gopher", "fail"))
// Output:
// 4
// 8
// -1
}
func ExampleLastIndexByte() {
fmt.Println(strings.LastIndexByte("Hello, world", 'l'))
fmt.Println(strings.LastIndexByte("Hello, world", 'o'))
fmt.Println(strings.LastIndexByte("Hello, world", 'x'))
// Output:
// 10
// 8
// -1
}
func ExampleLastIndexFunc() {
fmt.Println(strings.LastIndexFunc("go 123", unicode.IsNumber))
fmt.Println(strings.LastIndexFunc("123 go", unicode.IsNumber))
fmt.Println(strings.LastIndexFunc("go", unicode.IsNumber))
// Output:
// 5
// 2
// -1
}
func ExampleJoin() {
s := []string{"foo", "bar", "baz"}
fmt.Println(strings.Join(s, ", "))
// Output: foo, bar, baz
}
func ExampleRepeat() {
fmt.Println("ba" + strings.Repeat("na", 2))
// Output: banana
}
func ExampleReplace() {
fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
// Output:
// oinky oinky oink
// moo moo moo
}
func ExampleReplaceAll() {
fmt.Println(strings.ReplaceAll("oink oink oink", "oink", "moo"))
// Output:
// moo moo moo
}
func ExampleSplit() {
fmt.Printf("%q\n", strings.Split("a,b,c", ","))
fmt.Printf("%q\n", strings.Split("a man a plan a canal panama", "a "))
fmt.Printf("%q\n", strings.Split(" xyz ", ""))
fmt.Printf("%q\n", strings.Split("", "Bernardo O'Higgins"))
// Output:
// ["a" "b" "c"]
// ["" "man " "plan " "canal panama"]
// [" " "x" "y" "z" " "]
// [""]
}
func ExampleSplitN() {
fmt.Printf("%q\n", strings.SplitN("a,b,c", ",", 2))
z := strings.SplitN("a,b,c", ",", 0)
fmt.Printf("%q (nil = %v)\n", z, z == nil)
// Output:
// ["a" "b,c"]
// [] (nil = true)
}
func ExampleSplitAfter() {
fmt.Printf("%q\n", strings.SplitAfter("a,b,c", ","))
// Output: ["a," "b," "c"]
}
func ExampleSplitAfterN() {
fmt.Printf("%q\n", strings.SplitAfterN("a,b,c", ",", 2))
// Output: ["a," "b,c"]
}
func ExampleTitle() {
// Compare this example to the ToTitle example.
fmt.Println(strings.Title("her royal highness"))
fmt.Println(strings.Title("loud noises"))
fmt.Println(strings.Title("хлеб"))
// Output:
// Her Royal Highness
// Loud Noises
// Хлеб
}
func ExampleToTitle() {
// Compare this example to the Title example.
fmt.Println(strings.ToTitle("her royal highness"))
fmt.Println(strings.ToTitle("loud noises"))
fmt.Println(strings.ToTitle("хлеб"))
// Output:
// HER ROYAL HIGHNESS
// LOUD NOISES
// ХЛЕБ
}
func ExampleToTitleSpecial() {
fmt.Println(strings.ToTitleSpecial(unicode.TurkishCase, "dünyanın ilk borsa yapısı Aizonai kabul edilir"))
// Output:
// DÜNYANIN İLK BORSA YAPISI AİZONAİ KABUL EDİLİR
}
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.Println(strings.Map(rot13, "'Twas brillig and the slithy gopher..."))
// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
}
func ExampleNewReplacer() {
r := strings.NewReplacer("<", "&lt;", ">", "&gt;")
fmt.Println(r.Replace("This is <b>HTML</b>!"))
// Output: This is &lt;b&gt;HTML&lt;/b&gt;!
}
func ExampleToUpper() {
fmt.Println(strings.ToUpper("Gopher"))
// Output: GOPHER
}
func ExampleToUpperSpecial() {
fmt.Println(strings.ToUpperSpecial(unicode.TurkishCase, "örnek iş"))
// Output: ÖRNEK İŞ
}
func ExampleToLower() {
fmt.Println(strings.ToLower("Gopher"))
// Output: gopher
}
func ExampleToLowerSpecial() {
fmt.Println(strings.ToLowerSpecial(unicode.TurkishCase, "Önnek İş"))
// Output: önnek iş
}
func ExampleTrim() {
fmt.Print(strings.Trim("¡¡¡Hello, Gophers!!!", "!¡"))
// Output: Hello, Gophers
}
func ExampleTrimSpace() {
fmt.Println(strings.TrimSpace(" \t\n Hello, Gophers \n\t\r\n"))
// Output: Hello, Gophers
}
func ExampleTrimPrefix() {
var s = "¡¡¡Hello, Gophers!!!"
s = strings.TrimPrefix(s, "¡¡¡Hello, ")
s = strings.TrimPrefix(s, "¡¡¡Howdy, ")
fmt.Print(s)
// Output: Gophers!!!
}
func ExampleTrimSuffix() {
var s = "¡¡¡Hello, Gophers!!!"
s = strings.TrimSuffix(s, ", Gophers!!!")
s = strings.TrimSuffix(s, ", Marmots!!!")
fmt.Print(s)
// Output: ¡¡¡Hello
}
func ExampleTrimFunc() {
fmt.Print(strings.TrimFunc("¡¡¡Hello, Gophers!!!", func(r rune) bool {
return !unicode.IsLetter(r) && !unicode.IsNumber(r)
}))
// Output: Hello, Gophers
}
func ExampleTrimLeft() {
fmt.Print(strings.TrimLeft("¡¡¡Hello, Gophers!!!", "!¡"))
// Output: Hello, Gophers!!!
}
func ExampleTrimLeftFunc() {
fmt.Print(strings.TrimLeftFunc("¡¡¡Hello, Gophers!!!", func(r rune) bool {
return !unicode.IsLetter(r) && !unicode.IsNumber(r)
}))
// Output: Hello, Gophers!!!
}
func ExampleTrimRight() {
fmt.Print(strings.TrimRight("¡¡¡Hello, Gophers!!!", "!¡"))
// Output: ¡¡¡Hello, Gophers
}
func ExampleTrimRightFunc() {
fmt.Print(strings.TrimRightFunc("¡¡¡Hello, Gophers!!!", func(r rune) bool {
return !unicode.IsLetter(r) && !unicode.IsNumber(r)
}))
// Output: ¡¡¡Hello, Gophers
}
func ExampleToValidUTF8() {
fmt.Printf("%s\n", strings.ToValidUTF8("abc", "\uFFFD"))
fmt.Printf("%s\n", strings.ToValidUTF8("a\xffb\xC0\xAFc\xff", ""))
fmt.Printf("%s\n", strings.ToValidUTF8("\xed\xa0\x80", "abc"))
// Output:
// abc
// abc
// abc
}