Appending is a really common operation when programming, but how do we append two arrays / slices in Golang?

Well, first lets try it:

myStringSlice := []string{"first", "second", "third"}
myStringSlice = append(myStringSlice, []string{"fourth", "fift"})

But this error pops up:

cannot use []string literal (type []string) as type string in append

Then how do we do this? We could iterate with a for but it doesn’t look nice.

The alternative option to append on arrays / slices in GoLang is to add the “…” syntax after the array / slice:

myStringSlice := []string{"first", "second", "third"}

//ERROR!
//myStringSlice = append(myStringSlice, []string{"fourth", "fift"})

myStringSlice = append(myStringSlice, []string{"fourth", "fift"}...)

myStringSlice = append(myStringSlice, "sixth", "seventh")

fmt.Println(myStringSlice))

Under the hood

“…” is syntax for variadic arguments in Go, aka it changes an slice into a multiple arguments in the function call

The code

Github Link