package main

import (
    "fmt"
    "math"
    "regexp"
    "strconv"
    "strings"
)

func main() {

    stringToTrim := "\t\t\n   Go \tis\t Awesome \t\t"
    trimResult := strings.TrimSpace(stringToTrim)
    fmt.Println(trimResult)

    stringWithSpaces := "\t\t\n   Go \tis\n Awesome \t\t"
    r := regexp.MustCompile("
 
\\s+")
    replace := r.ReplaceAllString(stringWithSpaces, " ")
    fmt.Println(replace)

    needSpace := "need space"
    fmt.Println(pad(needSpace, 14, "CENTER"))
    fmt.Println(pad(needSpace, 14, "LEFT"))
}

func pad(input string, padLen int, align string) string {
    inputLen := len(input)

    if
 
 inputLen >= padLen {
        return input
    }

    repeat := padLen - inputLen
    var output string
    switch align {
    case "RIGHT":
        output = fmt.Sprintf("% "+strconv.Itoa(-padLen)+"s", input)
    case "LEFT":
        output = fmt.Sprintf("% "+strconv.Itoa(padLen)+"s", input)
    case
 
 "CENTER":
        bothRepeat := float64(repeat) / float64(2)
        left := int(math.Floor(bothRepeat)) + inputLen
        right := int(math.Ceil(bothRepeat))
        output = fmt.Sprintf("% "+strconv.Itoa(left)+"s% "+strconv.Itoa(right)+"s", input, "")
    }
    return output
}

/*
Go  is   Awesome
 Go is Awesome
  need space
    need space

*/

2.11 whitespace 去掉空格