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func Compare




Compare returns an integer comparing two strings lexicographically. The result
will be 0 if a==b, -1 if a < b, and +1 if a > b.

Compare is included only for symmetry with package bytes. It is usually clearer
and always faster to use the built-in string comparison operators ==, <, >, and
so on.


Example:

fmt.Println(strings.Compare(“a”, “b”))
fmt.Println(strings.Compare(“a”, “a”))
fmt.Println(strings.Compare(“b”, “a”))
// Output:
// -1
// 0
// 1

func 


  1. func Contains(s, substr ) bool


Contains reports whether substr is within s.


Example:

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 ContainsAny


  1. func ContainsAny(s, chars string)


ContainsAny reports whether any Unicode code points in chars are within s.


Example:

fmt.Println(strings.ContainsAny(“team”, “i”))
fmt.Println(strings.ContainsAny(“failure”, “u & i”))
fmt.Println(strings.ContainsAny(“foo”, “”))
fmt.Println(strings.ContainsAny(“”, “”))
// Output:
// false
// true
// false
// false

func 


  1. func ContainsRune(s , r rune)


ContainsRune reports whether the Unicode code point r is within s.


Example:

// 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 


  1. func Count(s, substr ) int


Count counts the number of non-overlapping instances of substr in s. If substr
is an empty string, Count returns 1 + the number of Unicode code points in s.


Example:

fmt.Println(strings.Count(“cheese”, “e”))
fmt.Println(strings.Count(“five”, “”)) // before & after each rune
// Output:
// 3
// 5

func EqualFold




    EqualFold reports whether s and t, interpreted as UTF-8 strings, are equal under
    Unicode case-folding.


    Example:

    fmt.Println(strings.EqualFold(“Go”, “go”))
    // Output: true

    func 


    1. func Fields(s ) []string


    Fields splits the string s around each instance of one or more consecutive white
    space characters, as defined by unicode.IsSpace, returning a slice of substrings
    of s or an empty slice if s contains only white space.


    Example:

    fmt.Printf(“Fields are: %q”, strings.Fields(“ foo bar baz “))
    // Output: Fields are: [“foo” “bar” “baz”]

    func FieldsFunc


    1. func FieldsFunc(s string, f func() bool) []


    FieldsFunc splits the string s at each run of Unicode code points c satisfying
    f(c) and returns an array of slices of s. If all code points in s satisfy f(c)
    or the string is empty, an empty slice is returned. FieldsFunc makes no
    guarantees about the order in which it calls f(c). If f does not return
    consistent results for a given c, FieldsFunc may crash.


    Example:

    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 


    1. func HasPrefix(s, prefix ) bool


    HasPrefix tests whether the string s begins with prefix.


    Example:

    fmt.Println(strings.HasPrefix(“Gopher”, “Go”))
    fmt.Println(strings.HasPrefix(“Gopher”, “C”))
    fmt.Println(strings.HasPrefix(“Gopher”, “”))
    // Output:
    // true
    // false
    // true

    func HasSuffix


    1. func HasSuffix(s, suffix string)


    HasSuffix tests whether the string s ends with suffix.


    Example:

    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 


    1. func Index(s, substr ) int


    Index returns the index of the first instance of substr in s, or -1 if substr is
    not present in s.


    Example:

    fmt.Println(strings.Index(“chicken”, “ken”))
    fmt.Println(strings.Index(“chicken”, “dmr”))
    // Output:
    // 4
    // -1

    func IndexAny


    1. func IndexAny(s, chars string)


    IndexAny returns the index of the first instance of any Unicode code point from
    chars in s, or -1 if no Unicode code point from chars is present in s.


    Example:

    fmt.Println(strings.IndexAny(“chicken”, “aeiouy”))
    fmt.Println(strings.IndexAny(“crwth”, “aeiouy”))
    // Output:
    // 2
    // -1

    func 


    1. func IndexByte(s , c byte)


    IndexByte returns the index of the first instance of c in s, or -1 if c is not
    present in s.


    Example:

    fmt.Println(strings.IndexByte(“golang”, ‘g’))
    fmt.Println(strings.IndexByte(“gophers”, ‘h’))
    fmt.Println(strings.IndexByte(“golang”, ‘x’))
    // Output:
    // 0
    // 3
    // -1


    1. func IndexFunc(s , f func(rune) ) int


    IndexFunc returns the index into s of the first Unicode code point satisfying
    f(c), or -1 if none do.


    Example:

    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 IndexRune


    1. func IndexRune(s string, r ) int


    IndexRune returns the index of the first instance of the Unicode code point r,
    or -1 if rune is not present in s. If r is utf8.RuneError, it returns the first
    instance of any invalid UTF-8 byte sequence.


    Example:

    fmt.Println(strings.IndexRune(“chicken”, ‘k’))
    fmt.Println(strings.IndexRune(“chicken”, ‘d’))
    // Output:
    // 4
    // -1

    func Join


    1. func Join(a []string, sep ) string


    Join concatenates the elements of a to create a single string. The separator
    string sep is placed between elements in the resulting string.


    Example:

    s := []string{“foo”, “bar”, “baz”}
    fmt.Println(strings.Join(s, “, “))
    // Output: foo, bar, baz

    func LastIndex


    1. func LastIndex(s, substr string)


    LastIndex returns the index of the last instance of substr in s, or -1 if substr
    is not present in s.


    Example:

    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 


    1. func LastIndexAny(s, chars ) int


    LastIndexAny returns the index of the last instance of any Unicode code point
    from chars in s, or -1 if no Unicode code point from chars is present in s.


    Example:

    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 LastIndexByte


    1. func LastIndexByte(s string, c ) int


    LastIndexByte returns the index of the last instance of c in s, or -1 if c is
    not present in s.


    Example:

    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 LastIndexFunc


    1. func LastIndexFunc(s string, f func() bool)


    LastIndexFunc returns the index into s of the last Unicode code point satisfying
    f(c), or -1 if none do.


    Example:

    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 


    1. func Map(mapping func() rune, s ) string


    Map returns a copy of the string s with all its characters modified according to
    the mapping function. If mapping returns a negative value, the character is
    dropped from the string with no replacement.


    Example:

    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 Repeat


    1. func Repeat(s string, count ) string


    Repeat returns a new string consisting of count copies of the string s.

    It panics if count is negative or if the result of (len(s) count) overflows.


    Example:

    fmt.Println(“ba” + strings.Repeat(“na”, 2))
    // Output: banana

    func Replace


    1. func Replace(s, old, new string, n ) string


    Replace returns a copy of the string s with the first n non-overlapping
    instances of old replaced by new. If old is empty, it matches at the beginning
    of the string and after each UTF-8 sequence, yielding up to k+1 replacements for
    a k-rune string. If n < 0, there is no limit on the number of replacements.


    Example:

    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 Split




    Split slices s into all substrings separated by sep and returns a slice of the
    substrings between those separators.

    If s does not contain sep and sep is not empty, Split returns a slice of length
    1 whose only element is s.

    If sep is empty, Split splits after each UTF-8 sequence. If both s and sep are
    empty, Split returns an empty slice.

    It is equivalent to SplitN with a count of -1.


    Example:

    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 


    1. func SplitAfter(s, sep ) []string


    SplitAfter slices s into all substrings after each instance of sep and returns a
    slice of those substrings.

    If s does not contain sep and sep is not empty, SplitAfter returns a slice of
    length 1 whose only element is s.

    If sep is empty, SplitAfter splits after each UTF-8 sequence. If both s and sep
    are empty, SplitAfter returns an empty slice.

    It is equivalent to SplitAfterN with a count of -1.


    Example:

    fmt.Printf(“%q\n”, strings.SplitAfter(“a,b,c”, “,”))
    // Output: [“a,” “b,” “c”]

    func SplitAfterN


    1. func SplitAfterN(s, sep string, n ) []string


    SplitAfterN slices s into substrings after each instance of sep and returns a
    slice of those substrings.

    The count determines the number of substrings to return:

    n > 0: at most n substrings; the last substring will be the unsplit remainder.
    n == 0: the result is nil (zero substrings)
    n < 0: all substrings

    Edge cases for s and sep (for example, empty strings) are handled as described
    in the documentation for SplitAfter.


    Example:

    fmt.Printf(“%q\n”, strings.SplitAfterN(“a,b,c”, “,”, 2))
    // Output: [“a,” “b,c”]

    func SplitN


    1. func SplitN(s, sep string, n ) []string


    SplitN slices s into substrings separated by sep and returns a slice of the
    substrings between those separators.

    The count determines the number of substrings to return:

    n > 0: at most n substrings; the last substring will be the unsplit remainder.
    n == 0: the result is nil (zero substrings)
    n < 0: all substrings

    Edge cases for s and sep (for example, empty strings) are handled as described
    in the documentation for Split.


    Example:

    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 Title


    1. func Title(s string)


    Title returns a copy of the string s with all Unicode letters that begin words
    mapped to their title case.

    BUG(rsc): The rule Title uses for word boundaries does not handle Unicode
    punctuation properly.


    Example:

    fmt.Println(strings.Title(“her royal highness”))
    // Output: Her Royal Highness

    func 


    1. func ToLower(s ) string


    ToLower returns a copy of the string s with all Unicode letters mapped to their
    lower case.


    Example:

    fmt.Println(strings.ToLower(“Gopher”))
    // Output: gopher


    1. func ToLowerSpecial(c unicode., s string)


    ToLowerSpecial returns a copy of the string s with all Unicode letters mapped to
    their lower case, giving priority to the special casing rules.


    Example:

    fmt.Println(strings.ToLowerSpecial(unicode.TurkishCase, “Önnek İş”))
    // Output: önnek iş

    func 


    1. func ToTitle(s ) string


    ToTitle returns a copy of the string s with all Unicode letters mapped to their
    title case.


    Example:

    fmt.Println(strings.ToTitle(“loud noises”))
    fmt.Println(strings.ToTitle(“хлеб”))
    // Output:
    // LOUD NOISES
    // ХЛЕБ

    func ToTitleSpecial


    1. func ToTitleSpecial(c unicode., s string)


    ToTitleSpecial returns a copy of the string s with all Unicode letters mapped to
    their title case, giving priority to the special casing rules.


    Example:

    fmt.Println(strings.ToTitleSpecial(unicode.TurkishCase, “dünyanın ilk borsa yapısı Aizonai kabul edilir”))
    // Output:
    // DÜNYANIN İLK BORSA YAPISI AİZONAİ KABUL EDİLİR

    func 


    1. func ToUpper(s ) string


    ToUpper returns a copy of the string s with all Unicode letters mapped to their
    upper case.


    Example:

    fmt.Println(strings.ToUpper(“Gopher”))
    // Output: GOPHER

    func ToUpperSpecial


    1. func ToUpperSpecial(c unicode., s string)


    ToUpperSpecial returns a copy of the string s with all Unicode letters mapped to
    their upper case, giving priority to the special casing rules.


    Example:

    fmt.Println(strings.ToUpperSpecial(unicode.TurkishCase, “örnek iş”))
    // Output: ÖRNEK İŞ

    func 


    1. func Trim(s , cutset string)


    Trim returns a slice of the string s with all leading and trailing Unicode code
    points contained in cutset removed.


    Example:

    fmt.Print(strings.Trim(“¡¡¡Hello, Gophers!!!”, “!¡”))
    // Output: Hello, Gophers

    func 


    1. func TrimFunc(s , f func(rune) ) string


    TrimFunc returns a slice of the string s with all leading and trailing Unicode
    code points c satisfying f(c) removed.


    Example:

    fmt.Print(strings.TrimFunc(“¡¡¡Hello, Gophers!!!”, func(r rune) bool {
    return !unicode.IsLetter(r) && !unicode.IsNumber(r)
    }))
    // Output: Hello, Gophers

    func TrimLeft


    1. func TrimLeft(s string, cutset ) string


    TrimLeft returns a slice of the string s with all leading Unicode code points
    contained in cutset removed.


    Example:

    fmt.Print(strings.TrimLeft(“¡¡¡Hello, Gophers!!!”, “!¡”))
    // Output: Hello, Gophers!!!

    func TrimLeftFunc


    1. func TrimLeftFunc(s string, f func() bool)


    TrimLeftFunc returns a slice of the string s with all leading Unicode code
    points c satisfying f(c) removed.


    Example:

    fmt.Print(strings.TrimLeftFunc(“¡¡¡Hello, Gophers!!!”, func(r rune) bool {
    return !unicode.IsLetter(r) && !unicode.IsNumber(r)
    }))
    // Output: Hello, Gophers!!!

    func 


    1. func TrimPrefix(s, prefix ) string


    TrimPrefix returns s without the provided leading prefix string. If s doesn’t
    start with prefix, s is returned unchanged.


    Example:

    var s = “¡¡¡Hello, Gophers!!!”
    s = strings.TrimPrefix(s, “¡¡¡Hello, “)
    s = strings.TrimPrefix(s, “¡¡¡Howdy, “)
    fmt.Print(s)
    // Output: Gophers!!!

    func TrimRight


    1. func TrimRight(s string, cutset ) string


    TrimRight returns a slice of the string s, with all trailing Unicode code points
    contained in cutset removed.


    Example:

    fmt.Print(strings.TrimRight(“¡¡¡Hello, Gophers!!!”, “!¡”))
    // Output: ¡¡¡Hello, Gophers

    func TrimRightFunc


    1. func TrimRightFunc(s string, f func() bool)


    TrimRightFunc returns a slice of the string s with all trailing Unicode code
    points c satisfying f(c) removed.


    Example:

    fmt.Print(strings.TrimRightFunc(“¡¡¡Hello, Gophers!!!”, func(r rune) bool {
    return !unicode.IsLetter(r) && !unicode.IsNumber(r)
    }))
    // Output: ¡¡¡Hello, Gophers

    func 


    1. func TrimSpace(s ) string


    TrimSpace returns a slice of the string s, with all leading and trailing white
    space removed, as defined by Unicode.


    Example:

    fmt.Println(strings.TrimSpace(“ \t\n Hello, Gophers \n\t\r\n”))
    // Output: Hello, Gophers

    func TrimSuffix


    1. func TrimSuffix(s, suffix string)


    TrimSuffix returns s without the provided trailing suffix string. If s doesn’t
    end with suffix, s is returned unchanged.


    Example:

    var s = “¡¡¡Hello, Gophers!!!”
    s = strings.TrimSuffix(s, “, Gophers!!!”)
    s = strings.TrimSuffix(s, “, Marmots!!!”)
    fmt.Print(s)
    // Output: ¡¡¡Hello

    type 


    1. type Builder struct {
          // contains filtered or unexported fields
      }


    A Builder is used to efficiently build a string using Write methods. It
    minimizes memory copying. The zero value is ready to use. Do not copy a non-zero
    Builder.


    Example:

    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 (Builder) Grow


    1. func (b Builder) Grow(n )


    Grow grows b’s capacity, if necessary, to guarantee space for another n bytes.
    After Grow(n), at least n bytes can be written to b without another allocation.
    If n is negative, Grow panics.

    func (Builder) Len


    1. func (b Builder) Len()


    Len returns the number of accumulated bytes; b.Len() == len(b.String()).

    func (Builder) Reset




    Reset resets the Builder to be empty.

    func (Builder) String


    1. func (b Builder) String()


    String returns the accumulated string.

    func (Builder) Write


    1. func (b Builder) Write(p []) (int, )


    Write appends the contents of p to b’s buffer. Write always returns len(p), nil.

    func (Builder) WriteByte


    1. func (b Builder) WriteByte(c ) error


    WriteByte appends the byte c to b’s buffer. The returned error is always nil.


    1. func (b ) WriteRune(r rune) (, error)


    WriteRune appends the UTF-8 encoding of Unicode code point r to b’s buffer. It
    returns the length of r and a nil error.

    func (Builder) 


    1. func (b ) WriteString(s string) (, error)


    WriteString appends the contents of s to b’s buffer. It returns the length of s
    and a nil error.

    type 


    1. type Reader struct {
          // contains filtered or unexported fields
      }


    A Reader implements the io.Reader, io.ReaderAt, io.Seeker, io.WriterTo,
    io.ByteScanner, and io.RuneScanner interfaces by reading from a string.

    func 


    1. func NewReader(s ) Reader


    NewReader returns a new Reader reading from s. It is similar to
    bytes.NewBufferString but more efficient and read-only.

    func (Reader) 


    1. func (r ) Len() int


    Len returns the number of bytes of the unread portion of the string.

    func (Reader) 


    1. func (r ) Read(b []byte) (n , err error)



    func (Reader) 


    1. func (r ) ReadAt(b []byte, off ) (n int, err )



    func (Reader) ReadByte


    1. func (r Reader) ReadByte() (, error)



    func (Reader) 


    1. func (r ) ReadRune() (ch rune, size , err error)




    1. func (r ) Reset(s string)


    Reset resets the Reader to be reading from s.

    func (Reader) 


    1. func (r ) Seek(offset int64, whence ) (int64, )


    Seek implements the io.Seeker interface.

    func (Reader) Size


    1. func (r Reader) Size()


    Size returns the original length of the underlying string. Size is the number of
    bytes available for reading via ReadAt. The returned value is always the same
    and is not affected by calls to any other method.

    func (Reader) UnreadByte


    1. func (r Reader) UnreadByte()



    func (Reader) UnreadRune


    1. func (r Reader) UnreadRune()



    func (Reader) WriteTo


    1. func (r Reader) WriteTo(w .Writer) (n , err error)


    WriteTo implements the io.WriterTo interface.


    1. type Replacer struct {
          // contains filtered or unexported fields
      }


    Replacer replaces a list of strings with replacements. It is safe for concurrent
    use by multiple goroutines.

    func 


    1. func NewReplacer(oldnew …) Replacer


    NewReplacer returns a new Replacer from a list of old, new string pairs.
    Replacements are performed in order, without overlapping matches.


    Example:

    r := strings.NewReplacer(“<”, “<”, “>”, “>”)
    fmt.Println(r.Replace(“This is HTML!”))
    // Output: This is <b>HTML</b>!

    func (Replacer) Replace


    1. func (r Replacer) Replace(s ) string


    Replace returns a copy of s with all replacements performed.


    1. func (r *) WriteString(w io., s string) (n , err error)


    WriteString writes s to w with all replacements performed.

    Bugs