[Golang] First Letter of Chinese Character Pinyin

package first

import (
      "github.com/mozillazg/go-pinyin"
)

var a = pinyin.NewArgs()

func FirstLetterOfPinYin(r rune) string {
      result := pinyin.Pinyin(string(r), a)
      return string(result[0][0][0])
}

package first

import (
      "testing"
)

func TestFirstLetterOfPinYin(t *testing.T) {
      if FirstLetterOfPinYin('世') != "s" {
              t.Error("世")
      }
      if FirstLetterOfPinYin('界') != "j" {
              t.Error("界")
      }
}