package main
import (
  "fmt"
  "strconv"
)

func main() {
  a := "3.14"
  b, _ := strconv.ParseFloat(a, 64)
  fmt.Println("a:", a, "b:", b)
  fmt.Printf("字符串 '%s'  转换为浮点数为：%f\n", a, b)

  c := "156"
  d, err := strconv.Atoi(c)
  if err != nil {
    fmt.Println("转换失败", err)
  }
  fmt.Printf("字符串 '%s' 转换为整数位: %d\n", c, d)

  number := 123
  str := strconv.Itoa(number)
  fmt.Println("number:", number, "str:", str)
  fmt.Printf("整数 %d  转换为字符串为：'%s'\n", number, str)
}

$ go run string_change_int.go 
a: 3.14 b: 3.14
字符串 '3.14'  转换为浮点数为：3.140000
字符串 '156' 转换为整数位: 156
number: 123 str: 123
整数 123  转换为字符串为：'123'