在 Golang 中，如何在不完全忽略大小写的情况下按字母顺序对字符串列表进行排序？

Question

我希望字符串按字母顺序排序，并控制“A”是否在“a”之前。

在使用 strings.ToLower() 的 Less() 函数中无法实现这一点。有时“A”在“a”之前，有时在之后。

Answer 1

不是使用 比较整个字符串strings.ToLower，而是比较单个符文。https://play.golang.org/p/RUMlmrb7C3gtype ByCase []stringfunc (s ByCase) Len() int&nbsp; &nbsp; &nbsp; { return len(s) }func (s ByCase) Swap(i, j int) { s[i], s[j] = s[j], s[i] }func (s ByCase) Less(i, j int) bool {&nbsp; &nbsp; iRunes := []rune(s[i])&nbsp; &nbsp; jRunes := []rune(s[j])&nbsp; &nbsp; max := len(iRunes)&nbsp; &nbsp; if max > len(jRunes) {&nbsp; &nbsp; &nbsp; &nbsp; max = len(jRunes)&nbsp; &nbsp; }&nbsp; &nbsp; for idx := 0; idx < max; idx++ {&nbsp; &nbsp; &nbsp; &nbsp; ir := iRunes[idx]&nbsp; &nbsp; &nbsp; &nbsp; jr := jRunes[idx]&nbsp; &nbsp; &nbsp; &nbsp; lir := unicode.ToLower(ir)&nbsp; &nbsp; &nbsp; &nbsp; ljr := unicode.ToLower(jr)&nbsp; &nbsp; &nbsp; &nbsp; if lir != ljr {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return lir < ljr&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; // the lowercase runes are the same, so compare the original&nbsp; &nbsp; &nbsp; &nbsp; if ir != jr {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return ir < jr&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; // If the strings are the same up to the length of the shortest string,&nbsp;&nbsp; &nbsp; // the shorter string comes first&nbsp; &nbsp; return len(iRunes) < len(jRunes)}

Answer 2

这可能是一个解决方案：package mainimport (&nbsp; &nbsp; "strings"&nbsp; &nbsp; "sort"&nbsp; &nbsp; "fmt")var listOfStrings []string = []string{&nbsp; &nbsp; "mars bar",&nbsp; &nbsp; "milk-duds",&nbsp; &nbsp; "Mars bar",&nbsp; &nbsp; "milk",&nbsp; &nbsp; "milky-way",&nbsp; &nbsp; "Milk",&nbsp; &nbsp; "Milky-way",&nbsp; &nbsp; "mars",}type Alphabetic []stringfunc (list Alphabetic) Len() int { return len(list) }func (list Alphabetic) Swap(i, j int) { list[i], list[j] = list[j], list[i] }func (list Alphabetic) Less(i, j int) bool {&nbsp; &nbsp; var si string = list[i]&nbsp; &nbsp; var sj string = list[j]&nbsp; &nbsp; var si_lower = strings.ToLower(si)&nbsp; &nbsp; var sj_lower = strings.ToLower(sj)&nbsp; &nbsp; if si_lower == sj_lower {&nbsp; &nbsp; &nbsp; &nbsp; return si < sj&nbsp; &nbsp; }&nbsp; &nbsp; return si_lower < sj_lower}func main() {&nbsp; &nbsp; fmt.Println("UNSORTED")&nbsp; &nbsp; printStrings(listOfStrings)&nbsp; &nbsp; sort.Sort(Alphabetic(listOfStrings))&nbsp; &nbsp; fmt.Println()&nbsp; &nbsp; fmt.Println("SORTED ALPHABETICALLY")&nbsp; &nbsp; printStrings(listOfStrings)}func printStrings(slice []string) {&nbsp; &nbsp; for i := 0; i < len(slice); i++ {&nbsp; &nbsp; &nbsp; &nbsp; fmt.Println(slice[i])&nbsp; &nbsp; }}这是输出：UNSORTEDmars barmilk-dudsMars barmilkmilky-wayMilkMilky-waymarsSORTED ALPHABETICALLYmarsMars barmars barMilkmilkmilk-dudsMilky-waymilky-way

Answer 3

这是一个 Unicode 友好的方法，它利用strings.Map：package mainimport (&nbsp; &nbsp;"fmt"&nbsp; &nbsp;"sort"&nbsp; &nbsp;"strings"&nbsp; &nbsp;"unicode")type slice struct { sort.StringSlice }func (s slice) Less(d, e int) bool {&nbsp; &nbsp;t := strings.Map(unicode.ToUpper, s.StringSlice[d])&nbsp; &nbsp;u := strings.Map(unicode.ToUpper, s.StringSlice[e])&nbsp; &nbsp;return t < u}func main() {&nbsp; &nbsp;a := slice{&nbsp; &nbsp; &nbsp; sort.StringSlice{"a", "b", "A", "B"},&nbsp; &nbsp;}&nbsp; &nbsp;sort.Sort(a)&nbsp; &nbsp;fmt.Println(a.StringSlice) // [a A b B]}https://golang.org/pkg/strings#Map