Golang : Increment string example
Problem:
You need to create "copies" of a file, prevent user from overwriting files accidentally or need duplicate database content which has unique titles or slugs. Having increment string function is helpful in this kind of situation. How to do that?
Solution:
Increments a string by appending a number to it or increasing the number.
Below is a function to increment the string value that you can use or adapt to your own Golang code.
package main
import (
"fmt"
"os"
"strconv"
"strings"
)
func incrementString(str string, separator string, first int) string {
// set default values
// see https://www.socketloop.com/tutorials/golang-proper-way-to-set-function-argument-default-value
if separator == "" {
separator = "_"
}
if first == 0 || first < 0 {
first = 1
}
// test to see if str already has integer suffix(ends with _#)
test := strings.SplitN(str, separator, 2)
if len(test) >= 2 {
// increase file counter by 1
i, err := strconv.Atoi(test[1])
if err != nil {
fmt.Println(err)
os.Exit(1)
}
increased := i + first
return test[0] + separator + strconv.Itoa(increased)
} else {
return str + separator + strconv.Itoa(first)
}
}
func main() {
result := incrementString("file", "_", 0)
fmt.Println(result)
result = incrementString("file", "-", 2)
fmt.Println(result)
// increase by 1
result = incrementString("file_2", "", 1)
fmt.Println(result)
// increase by 2
result = incrementString("file_2", "", 2)
fmt.Println(result)
// increase by 100
result = incrementString("file_3", "", 100)
fmt.Println(result)
// change separator to # sign
result = incrementString("imagefiles", "#", 10)
fmt.Println(result)
// will NOT accept negative number. will change to default value of 1
result = incrementString("imagefiles", "#", -99)
fmt.Println(result)
}
Output:
file_1
file-2
file_3
file_4
file_103
imagefiles#10
imagefiles#1
Happy coding!
References:
See also : Golang : How to check if a string starts or ends with certain characters or words?
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+13.1k Golang : Calculate elapsed years or months since a date
+7.6k Gogland : Single File versus Go Application Run Configurations
+15.3k Golang : Get timezone offset from date or timestamp
+7.9k Golang : Load DSA public key from file example
+4.5k Java : Generate multiplication table example
+52k Golang : How to get time in milliseconds?
+6.3k Golang : Process non-XML/JSON formatted ASCII text file example
+11.7k Golang : Simple file scaning and remove virus example
+14.6k Golang : Convert(cast) int to float example
+5.1k Golang : Check if a word is countable or not
+22.8k Golang : Set and Get HTTP request headers example
+38.1k Golang : Read a text file and replace certain words