How to use iota in Golang?

Iota in Go is used to represent constant increasing sequences. When repeated in a constant, its value gets incremented after each specification. In this article, we will explore the different ways in which we can use iota in Go.

Let's first consider a very basic example, where we will declare multiple constants and use iota.

Example 1

Consider the code shown below

package main
import (
   "fmt"
)
const (
   first = iota
   second = iota
   third = iota
)
func main() {
   fmt.Println(first, second, third)
}

Output

If we run the command go run main.go, then we will get the following output in the terminal.

0 1 2

We can also omit the repetition of the iota keyword in the above example. Consider the code shown below.

Example 2

package main
import (
   "fmt"
)
const (
   first = iota
   second
   third
)
func main() {
   fmt.Println(first, second, third)
}

Output

If we run the command go run main.go, then we will get the following output in the terminal.

0 1 2

It is not necessary to start the iota with the default value; we can start it with 1 also.

Example 3

Consider the code shown below

package main
import (
   "fmt"
)
const (
   first = iota + 1
   second
   third
)
func main() {
   fmt.Println(first, second, third)
}

Output

If we run the command go run main.go, then we will get the following output in the terminal.

1 2 3

We can also skip the values while using iota.

Example 4

Consider the code shown below.

package main
import (
   "fmt"
)
const (
   first = iota + 1
   second
   _
   fourth
)
func main() {
   fmt.Println(first, second, fourth)
}

Output

If we run the command go run main.go, then we will get the following output in the terminal.

1 2 4