Question

我有一个简单的输入字符串，我需要阅读并计算重复的单词。

但是，在执行此操作时，我需要将字符串转换为小写字母，但有些函数如何将函数ToLower无效。

我已附上golang链接，请帮助我了解可能出现的问题。

https://play.golang.org/p/OnQW-pgQxqq

同样粘贴代码。

func main() {
    input := `
one
two Two
three Three Three;
four four four, four
five? five. five, five Five`
    countwords(input)
}

type kv struct {
    key string
    val int
}

type kvlist []kv

// need to define custome interface to make this work:
func (kv kvlist) Less(i, j int) bool { return kv[i].val < kv[j].val }
func (kv kvlist) Swap(i, j int)      { kv[i], kv[j] = kv[j], kv[i] }
func (kv kvlist) Len() int           { return len(kv) }

//sort the words by value
func sortmap(wordmap map[string]int) []kv {
    list := make(kvlist, len(wordmap))
    i := 0
    for k, v := range wordmap {
        list[i] = kv{k, v}
        i++
    }
    // we need to make few more modification to change this but,
    // for now lets assume it works.
    sort.Sort(sort.Reverse(list))
    return list
}

func countwords(str string) []kv {
    count := make(map[string]int)
    reg, err := regexp.Compile("[^a-zA-Z0-9 ]+")
    if err != nil {
        log.Fatal(err)
    }
    lines := strings.Split(str, "\n")
    for _, line := range lines {
        line := reg.ReplaceAllString(line, "")
        strings.ToLower(string(line))
        repeatwords := strings.Fields(line) // count the repeated words
        fmt.Println(repeatwords)
        for _, word := range repeatwords {
            if _, ok := count[word]; ok {
                count[word]++
            } else {
                count[word] = 1
            }
        }
    }
    //once counted now sort the map based on values(repeated words).
    ret := sortmap(count)
    fmt.Println(count)
    return ret
}

Answer 1

因此，基于docs，strings.ToLower需要一个字符串并且RETURNS是一个字符串，所以基本上你必须将ToLower的结果赋给一个变量，如下所示诀窍

line = strings.ToLower(string(line))

golang string.ToLower不工作

1 个答案: