问题
i := 123
s := string(i)
s is 'E', but what I want is "123"
Please tell me how can I get "123".
And in Java, I can do in this way:
String s = "ab" + "c" // s is "abc"
how can I concat
two strings in Go?
回答1:
Use the strconv package's Itoa
function.
For example:
package main
import (
"strconv"
"fmt"
)
func main() {
t := strconv.Itoa(123)
fmt.Println(t)
}
You can concat strings simply by +
'ing them, or by using the Join
function of the strings package.
回答2:
fmt.Sprintf("%v",value);
If you know the specific type of value use the corresponding formatter for example %d
for int
More info - fmt
回答3:
It is interesting to note that strconv.Itoa
is shorthand for
func FormatInt(i int64, base int) string
with base 10
For Example:
strconv.Itoa(123)
is equivalent to
strconv.FormatInt(int64(123), 10)
回答4:
fmt.Sprintf
, strconv.Itoa
and strconv.FormatInt
will do the job. But Sprintf
will use the package reflect
, and it will allocate one more object, so it's not a good choice.
回答5:
You can use fmt.Sprintf
See http://play.golang.org/p/bXb1vjYbyc for example.
回答6:
In this case both strconv
and fmt.Sprintf
do the same job but using the strconv
package's Itoa
function is the best choice, because fmt.Sprintf
allocate one more object during conversion.
check the benchmark here: https://gist.github.com/evalphobia/caee1602969a640a4530
see https://play.golang.org/p/hlaz_rMa0D for example.
回答7:
Converting int64
:
n := int64(32)
str := strconv.FormatInt(n, 10)
fmt.Println(str)
// Prints "32"
回答8:
ok,most of them have shown you something good. Let'me give you this:
// ToString Change arg to string
func ToString(arg interface{}, timeFormat ...string) string {
if len(timeFormat) > 1 {
log.SetFlags(log.Llongfile | log.LstdFlags)
log.Println(errors.New(fmt.Sprintf("timeFormat's length should be one")))
}
var tmp = reflect.Indirect(reflect.ValueOf(arg)).Interface()
switch v := tmp.(type) {
case int:
return strconv.Itoa(v)
case int8:
return strconv.FormatInt(int64(v), 10)
case int16:
return strconv.FormatInt(int64(v), 10)
case int32:
return strconv.FormatInt(int64(v), 10)
case int64:
return strconv.FormatInt(v, 10)
case string:
return v
case float32:
return strconv.FormatFloat(float64(v), 'f', -1, 32)
case float64:
return strconv.FormatFloat(v, 'f', -1, 64)
case time.Time:
if len(timeFormat) == 1 {
return v.Format(timeFormat[0])
}
return v.Format("2006-01-02 15:04:05")
case jsoncrack.Time:
if len(timeFormat) == 1 {
return v.Time().Format(timeFormat[0])
}
return v.Time().Format("2006-01-02 15:04:05")
case fmt.Stringer:
return v.String()
case reflect.Value:
return ToString(v.Interface(), timeFormat...)
default:
return ""
}
}
回答9:
package main
import (
"fmt"
"strconv"
)
func main(){
//First question: how to get int string?
intValue := 123
// keeping it in separate variable :
strValue := strconv.Itoa(intValue)
fmt.Println(strValue)
//Second question: how to concat two strings?
firstStr := "ab"
secondStr := "c"
s := firstStr + secondStr
fmt.Println(s)
}
来源:https://stackoverflow.com/questions/10105935/how-to-convert-an-int-value-to-string-in-go