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?
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?
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)
You can use fmt.Sprintf or strconv.FormatFloat
For example
package main
import (
"fmt"
)
func main() {
val := 14.7
s := fmt.Sprintf("%f", val)
fmt.Println(s)
}
fmt.Sprintf("%v",value);
If you know the specific type of value use the corresponding formatter for example %d
for int
More info - fmt
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 ""
}
}
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)
}
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.
Use the
strconv
package'sItoa
function.For example:
You can concat strings simply by
+
'ing them, or by using theJoin
function of thestrings
package.