golang类型转化

 int 转 float

var sum int = 17 
mean:= float32(sum)

  float 转 int

a := 5.0
b := int(a)

  string 转 int

i,_ := strconv.Atoi("3")
fmt.println(3 + i) // 6

  int 转 string

fmt.println("a" + strconv.Itoa(32)) // a32

interface 转 string

var v1 interface{}="asdf"
fmt.Println(v1.(string))

  interface 转 int

var v2 interface{}=123
fmt.Println(v2.(int)+1) //124

  string 转 []byte

var str string = "test"
var b []byte = []byte(str)

  []byte 转 string

var str string = string(b)
var str string = string(b[:]) //or

对象转json字符串

str,err:=json.Marshal(stu)

json字符串转对象

stb := &Student{} 
err = json.Unmarshal([]byte(strData), &stb)

Map转json

map1 := make(map[string]interface{})
map1["1"] = "hello"
map1["2"] = "world"
str, err := json.Marshal(map1)  //return []byte
fmt.Println("map to json", string(str))

  json转map

map2 := make(map[string]interface{}) 
err = json.Unmarshal([]byte(jsonStr), &map2)

  数组转string

str := string(arr[:]) // 字符数组

　newStr := strings.Join(arr, ",") // 字符串数组   string 转 数组

s = strings.Split("abc,abc", ",")
fmt.Println(s, len(s)) //[abc abc] 2