To return multiple values from a function in Golang or Go, you can use the return keyword followed by the values you need to return separated by a , symbol (comma). Finally, you need to declare the types of the returning values inside the brackets after the function parameters brackets.
TL;DR
package main
import (
"fmt"
"strings"
)
// getFirstAndLastName accepts a full name string
// and returns the first name and last name
// as the first and second return values
func getFirstAndLastName(fullname string) (string, string) {
// splitting the fullname single string by whitespace
names := strings.Split(fullname, " ")
// return the `names` array first element as the first return value
// and the second element as the second return value
return names[0], names[1]
}
func main() {
// call the `getFirstAndLastName` function
// and assign the first return value to the `firstName` variable
// and the second return value to the `lastName` variable
// using the `:=` (assignment) operator
firstName, lastName := getFirstAndLastName("John Doe")
// log it to the console
fmt.Println(firstName, lastName) // John Doe
}
For example, let's say we have a function that accepts a fullname of a user as a single string and returns the first name and the last name as separate return values.
To do that first let's create a function called getFirstAndLastname like this,
package main
func getFirstAndLastName(fullname string) (string, string) {
// cool code here
}
func main(){
}
NOTE: To know more about functions in Go see the blog on How to create a function in Golang or Go?
Now inside the function body, we can write the logic for separating the first name and the last name from the fullname.
The logic is to divide the full name string by whitespace. To do that we can use the Split() method from the strings standard package.
It can be done like this,
package main
// getFirstAndLastName accepts a full name string
// and returns the first name and last name
// as the first and second return values
func getFirstAndLastName(fullname string) (string, string) {
// splitting the fullname single string by whitespace
names := strings.Split(fullname, " ")
}
func main(){
}
As you can see code in the function body, we are splitting the full name single string whenever we encounter whitespace.
The names variable will be an array containing the split strings, such that we can assume that the first value in the names array is the first name and the second value is the last name for simplicity.
Now let's return the names array's first element as the first return value and the second element as the second return value separated by the , symbol (comma).
It can be done like this,
package main
// getFirstAndLastName accepts a full name string
// and returns the first name and last name
// as the first and second return values
func getFirstAndLastName(fullname string) (string, string) {
// splitting the fullname single string by whitespace
names := strings.Split(fullname, " ")
// return the `names` array first element as the first return value
// and the second element as the second return value
return names[0], names[1]
}
func main(){
}
Now in the main function let's call the function and to get the return values from the getFirstAndLastName function, we can assign 2 variables called firstName and lastName separated by the , symbol and then use the := operator to assign the return values from the function respectively.
It can be done like this,
package main
// getFirstAndLastName accepts a full name string
// and returns the first name and last name
// as the first and second return values
func getFirstAndLastName(fullname string) (string, string) {
// splitting the fullname single string by whitespace
names := strings.Split(fullname, " ")
// return the `names` array first element as the first return value
// and the second element as the second return value
return names[0], names[1]
}
func main(){
// call the `getFirstAndLastName` function
// and assign the first return value to the `firstName` variable
// and the second return value to the `lastName` variable
// using the `:=` (assignment) operator
firstName, lastName := getFirstAndLastName("John Doe")
}
Finally, let's console the firstName and the lastName variable to the console using the Println() method from the fmt standard package like this,
package main
import (
"fmt"
"strings"
)
// getFirstAndLastName accepts a full name string
// and returns the first name and last name
// as the first and second return values
func getFirstAndLastName(fullname string) (string, string) {
// splitting the fullname single string by whitespace
names := strings.Split(fullname, " ")
// return the `names` array first element as the first return value
// and the second element as the second return value
return names[0], names[1]
}
func main() {
// call the `getFirstAndLastName` function
// and assign the first return value to the `firstName` variable
// and the second return value to the `lastName` variable
// using the `:=` (assignment) operator
firstName, lastName := getFirstAndLastName("John Doe")
// log it to the console
fmt.Println(firstName, lastName) // John Doe
}
We have successfully returned multiple values and assigned them to 2 variables in the Go. Yay 🥳!
See the above code live in The Go Playground.
That's all 😃!