s := strconv.Itoa(i)
等价于s := strconv.FormatInt(int64(i), 10)

i := int64(123)
s := strconv.FormatInt(i, 10)

i, err := strconv.Atoi(s)

i, err := strconv.ParseInt(s, 10, 64)

v := 3.1415926535
s1 := strconv.FormatFloat(v, 'E', -1, 32)//float32s2 := strconv.FormatFloat(v, 'E', -1, 64)//float64

s := "3.1415926535"
v1, err := strconv.ParseFloat(v, 32)
v2, err := strconv.ParseFloat(v, 64)

//string到int 
int,err:=strconv.Atoi(string) 
//string到int64 
int64, err := strconv.ParseInt(string, 10, 64) 
//int到string 
string:=strconv.Itoa(int) 
//int64到string 
string:=strconv.FormatInt(int64,10)
//string到float32(float64)
float,err := strconv.ParseFloat(string,32/64)
//float到string
string := strconv.FormatFloat(float32, 'E', -1, 32)
string := strconv.FormatFloat(float64, 'E', -1, 64)
// 'b' (-ddddp±ddd，二进制指数)
// 'e' (-d.dddde±dd，十进制指数)
// 'E' (-d.ddddE±dd，十进制指数)
// 'f' (-ddd.dddd，没有指数)
// 'g' ('e':大指数，'f':其它情况)
// 'G' ('E':大指数，'f':其它情况)