Go join string
last modified April 11, 2024
In this article we show how to join strings in Golang.
To join strings, we can use the + operator, fmt.Sprintf function, and strings.Join function.
Go join strings with + operator
Many programming languages use the + operator to join strings.
main.go
package main
import “fmt”
func main() {
w1 := "old"
w2 := "falcon"
msg := w1 + " " + w2
fmt.Println(msg)
}
Two words are joined in the example. We also add a space character between them.
$ go run main.go old falcon
Go join strings with fmt.Sprintf
The fmt.Sprintf function builds a string according to the given format specifiers and returns the resulting string.
main.go
package main
import “fmt”
func main() {
w1 := "old"
w2 := "falcon"
msg := fmt.Sprintf("%s %s", w1, w2)
fmt.Println(msg)
}
The example builds a message by joining two words.
Go join strings with bytes.Buffer
A bytes.Buffer is a variable-sized buffer of bytes with Read and Write methods.
main.go
package main
import ( “bytes” “fmt” )
func main() {
var buf bytes.Buffer
buf.WriteString("an ")
buf.WriteString("old ")
buf.WriteString("falcon")
fmt.Println(buf.String())
}
In the example, we write strings to the bytes buffer with WriteString and then convert the bytes into a final string with String function.
$ go run main.go an old falcon
Go strings.Join
The strings.Join function joins string elements of a slice/array into one string. The separator string is placed between elements in the resulting string.
fmt_funs.go
package main
import ( “fmt” “strings” )
func main() {
words := []string{"an", "old", "falcon"}
msg := strings.Join(words, " ")
fmt.Println(msg)
}
We have a slice of words. We join them with strings.Join, utilizing a single space as a separator.
Go String function
The String function of an object is called when it is passed to any of the print functions. It is commonly used to display a human-readable representation of the object.
main.go
package main
import ( “fmt” )
type User struct { Name string Occupation string }
func (u User) String() string {
return fmt.Sprintf("%s is a(n) %s", u.Name, u.Occupation)
}
func main() {
u1 := User{"John Doe", "gardener"}
u2 := User{"Roger Roe", "driver"}
fmt.Println(u1)
fmt.Println(u2)
}
In the example, we use the fmt.Sprintf function to generate an output of a User type.
$ go run main.go John Doe is a(n) gardener Roger Roe is a(n) driver
Source
The Go Programming Language Specification
In this article we have showed how to join strings in Golang.
Author
My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.
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