Go语言如何反转字符串中的单词顺序

package main

import (
    "fmt"
    "strings"
)

func reverseWords(s string) string {
    words := strings.Fields(s) // strings.Fields 会自动去除多余空格
    n := len(words)
    for i := 0; i < n/2; i++ {
        words[i], words[n-i-1] = words[n-i-1], words[i]
    }
    return strings.Join(words, " ")
}

func main() {
    s := "the sky is blue"
    reversed := reverseWords(s)
    fmt.Println(reversed) // Output: blue is sky the

    s2 := "  hello world  "
    reversed2 := reverseWords(s2)
    fmt.Println(reversed2) // Output: world hello
}

package main

import (
    "fmt"
    "regexp"
    "strings"
)

func reverseWordsSplit(s string) string {
    words := strings.Split(s, " ")
    var filteredWords []string
    for _, word := range words {
        if word != "" {
            filteredWords = append(filteredWords, word)
        }
    }

    n := len(filteredWords)
    for i := 0; i < n/2; i++ {
        filteredWords[i], filteredWords[n-i-1] = filteredWords[n-i-1], filteredWords[i]
    }
    return strings.Join(filteredWords, " ")
}

func reverseWordsRegexp(s string) string {
    re := regexp.MustCompile(`\s+`)
    words := re.Split(s, -1)

    var filteredWords []string
    for _, word := range words {
        if word != "" {
            filteredWords = append(filteredWords, word)
        }
    }

    n := len(filteredWords)
    for i := 0; i < n/2; i++ {
        filteredWords[i], filteredWords[n-i-1] = filteredWords[n-i-1], filteredWords[i]
    }
    return strings.Join(filteredWords, " ")
}

func main() {
    s := "the sky is blue"
    reversed := reverseWordsSplit(s)
    fmt.Println(reversed)

    s2 := "  hello   world  "
    reversed2 := reverseWordsSplit(s2)
    fmt.Println(reversed2)

    s3 := "the sky is blue"
    reversed3 := reverseWordsRegexp(s3)
    fmt.Println(reversed3)

    s4 := "  hello   world  "
    reversed4 := reverseWordsRegexp(s4)
    fmt.Println(reversed4)
}