Go Recursion Function

Recursive Functions in Go

• In Go, functions can be recursive, meaning a function can call itself. A recursive function must have a termination condition—a condition that eventually stops the recursion—to avoid infinite loops and excessive resource use.

Example 1: Counting Using Recursion

• In this example, the countUp function recursively prints numbers from the given starting point up to 10. The recursion stops when the number reaches 11.

package main
import (
"fmt"
)
func countUp(x int) {
if x == 11 {
return
}
fmt.Println(x)
countUp(x + 1)
}
func main() {
countUp(1)
}

Output:

1
2
3
4
5
6
7
8
9
10

Why Use Recursion?

• Recursion is a powerful concept in programming and mathematics. It allows you to break down complex problems into simpler ones. When implemented correctly, recursive functions can be concise and elegant.
• However, use caution: recursive functions that lack a proper exit condition can lead to infinite loops and high memory usage.

Example 2: Factorial Using Recursion

• The factorial of a number n (denoted as n!) is the product of all positive integers less than or equal to n. For example, 4! = 4 × 3 × 2 × 1 = 24.

The following recursive function calculates the factorial of a number:

package main
import (
"fmt"
)
func factorial(x float64) float64 {
if x > 0 {
return x * factorial(x-1)
}
return 1
}
func main() {
fmt.Println(factorial(4))
}

Output:

24

Summary

• Recursive functions call themselves to solve a smaller piece of a problem.
• Always include a base case (stop condition) to avoid infinite recursion.
• Recursion can make your code cleaner and more expressive when used correctly.