Go by Example: Recursion

Go by Example : Recursion

Go supports recursive functions . Here’s a classic example.

package main
import "fmt"

This fact function calls itself until it reaches the base case of fact(0) .

func fact(n int) int {
    if n == 0 {
        return 1
    }
    return n * fact(n-1)
}
func main() {
    fmt.Println(fact(7))

Closures can also be recursive, but this requires the closure to be declared with a typed var explicitly before it’s defined.

    var fib func(n int) int
    fib = func(n int) int {
        if n < 2 {
            return n
        }

Since fib was previously declared in main , Go knows which function to call with fib here.

        return fib(n-1) + fib(n-2)
    }
    fmt.Println(fib(7))
}
$ go run recursion.go 
5040
13

Next example: Range over Built-in Types .