如何在Golang中将跟随者字符连接到字符串，直到达到定义的最大长度？

Question

<kbd>Input</kbd><kbd>Output</kbd>
<kbd>abc    </kbd><kbd>abc___</kbd>
<kbd>a        </kbd><kbd>a___    </kbd>
<kbd>abcde</kbd><kbd>abcde_</kbd>

Attempt

package main

import "fmt"
import "unicode/utf8"

func main() {
    input := "abc"

    if utf8.RuneCountInString(input) == 1 {
        fmt.Println(input + "_____")
    } else if utf8.RuneCountInString(input) == 2 {
        fmt.Println(input + "____")
    } else if utf8.RuneCountInString(input) == 3 {
        fmt.Println(input + "___")
    } else if utf8.RuneCountInString(input) == 4 {
        fmt.Println(input + "__")
    } else if utf8.RuneCountInString(input) == 5 {
        fmt.Println(input + "_")
    } else {
        fmt.Println(input)
    }
}

returns

abc___

Discussion

Although the code is creating the expected output, it looks very verbose and devious.

Question

Is there a concise way?

Answer 1

The strings package has a Repeat function, so something like

input += strings.Repeat("_", desiredLen - utf8.RuneCountInString(input))

would be simpler. You should probably check that desiredLen is smaller than inpult length first.