Go语言实现十进制、二进制、八进制、十六进制的转换

除了使用strconv.ParseInt()和strconv.FormatInt()来进行进制间的转换，我们还可以尝试通过数学运算来自己实现

package convert

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

// Decimal to binary
func DecBin(n int64) string {
   if n < 0 {
      log.Println("Decimal to binary error: the argument must be greater than zero.")
      return ""
   }
   if n == 0 {
      return "0"
   }
   s := ""
   for q := n; q > 0; q = q / 2 {
      m := q % 2
      s = fmt.Sprintf("%v%v", m, s)
   }
   return s
}

// Decimal to octal
func DecOct(d int64) int64 {
   if d == 0 {
      return 0
   }
   if d < 0 {
      log.Println("Decimal to octal error: the argument must be greater than zero.")
      return -1
   }
   s := ""
   for q := d; q > 0; q = q / 8 {
      m := q % 8
      s = fmt.Sprintf("%v%v", m, s)
   }
   n, err := strconv.Atoi(s)
   if err != nil {
      log.Println("Decimal to octal error:", err.Error())
      return -1
   }
   return int64(n)
}

// Decimal to hexadecimal
func DecHex(n int64) string {
   if n < 0 {
      log.Println("Decimal to hexadecimal error: the argument must be greater than zero.")
      return ""
   }
   if n == 0 {
      return "0"
   }
   hex := map[int64]int64{10: 65, 11: 66, 12: 67, 13: 68, 14: 69, 15: 70}
   s := ""
   for q := n; q > 0; q = q / 16 {
      m := q % 16
      if m > 9 && m < 16 {
         m = hex[m]
         s = fmt.Sprintf("%v%v", string(m), s)
         continue
      }
      s = fmt.Sprintf("%v%v", m, s)
   }
   return s
}

// Binary to decimal
func BinDec(b string) (n int64) {
   s := strings.Split(b, "")
   l := len(s)
   i := 0
   d := float64(0)
   for i = 0; i < l; i++ {
      f, err := strconv.ParseFloat(s[i], 10)
      if err != nil {
         log.Println("Binary to decimal error:", err.Error())
         return -1
      }
      d += f * math.Pow(2, float64(l-i-1))
   }
   return int64(d)
}

// Octal to decimal
func OctDec(o int64) (n int64) {
   s := strings.Split(strconv.Itoa(int(o)), "")
   l := len(s)
   i := 0
   d := float64(0)
   for i = 0; i < l; i++ {
      f, err := strconv.ParseFloat(s[i], 10)
      if err != nil {
         log.Println("Octal to decimal error:", err.Error())
         return -1
      }
      d += f * math.Pow(8, float64(l-i-1))
   }
   return int64(d)
}

// Hexadecimal to decimal
func HexDec(h string) (n int64) {
   s := strings.Split(strings.ToUpper(h), "")
   l := len(s)
   i := 0
   d := float64(0)
   hex := map[string]string{"A": "10", "B": "11", "C": "12", "D": "13", "E": "14", "F": "15"}
   for i = 0; i < l; i++ {
      c := s[i]
      if v, ok := hex[c]; ok {
         c = v
      }
      f, err := strconv.ParseFloat(c, 10)
      if err != nil {
         log.Println("Hexadecimal to decimal error:", err.Error())
         return -1
      }
      d += f * math.Pow(16, float64(l-i-1))
   }
   return int64(d)
}

// Octal to binary
func OctBin(o int64) string {
   d := OctDec(o)
   if d == -1 {
      return ""
   }
   return DecBin(d)
}

// Hexadecimal to binary
func HexBin(h string) string {
   d := HexDec(h)
   if d == -1 {
      return ""
   }
   return DecBin(d)
}

// Binary to octal
func BinOct(b string) int64 {
   d := BinDec(b)
   if d == -1 {
      return -1
   }
   return DecOct(d)
}

// Binary to hexadecimal
func BinHex(b string) string {
   d := BinDec(b)
   if d == -1 {
      return ""
   }
   return DecHex(d)
}