Golang : Transform comma separated string to slice example

Got a request from a junior software developer from India. Her question is how to convert a given comma-separated string to slice or array in Golang.

For example:

from A,B,C,D

to [A B C D]

It is pretty common to encounter comma separated string in software development world. Below are two code examples on how to transform a comma-separated string to slice and back to a comma-separated string. To achieve this, use the strings.Fields() and strings.Join() functions. However, care must be taken to ensure that the comma in the input string must be removed first. Otherwise, the result will not be a slice that you can perform operations on properly.

Here you go!

---

 package main

 import (
 "fmt"
 "strings"
 )

 func main() {

 str := "A,B,C,D"

 fmt.Println(str)

 // first, clean/remove the comma
 cleaned := strings.Replace(str, ",", " ", -1)

 // convert 'clened' comma separated string to slice
 strSlice := strings.Fields(cleaned)

 fmt.Println(strSlice)

 //NOTE : If we don't clean/remove the comma from the string
 // the resultant strSlice will look like a slice but....
 // you won't be able to perform operation on it
 // such as strSlice[:1]

 fmt.Println(strSlice[:1]) // test if this is a SLICE or not

 }

---

Output:

A,B,C,D

[A B C D]

[A]

and back to comma-separated string

---

 package main

 import (
 "fmt"
 "strings"
 )

 func main() {

 strSlice := []string{"A", "B", "C", "D"}

 fmt.Println(strSlice)

 // convert slice back to comma-separated string
 str := strings.Join(strSlice, ",")

 fmt.Println(str)
 }

---

Output:

Notice the square brackets and the comma?

[A B C D]

A,B,C,D

Happy coding!

References:

https://www.socketloop.com/tutorials/golang-how-to-join-strings

https://www.socketloop.com/tutorials/golang-convert-string-to-array-slice