Go Recursion Functions
Recursion Functions
Go accepts recursion functions. A function is recursive if it calls itself and reaches a stop condition.
In the following example, testcount() is a function that calls itself. We use the x variable as the data, which
increments with 1 (x + 1) every time we recurse. The recursion ends when the x
variable equals to 11 (x == 11).
Example
package main
import ("fmt")
func testcount(x int) int {
if x == 11 {
return 0
}
fmt.Println(x)
return testcount(x
+ 1)
}
func main(){
testcount(1)
}
Result:
1
2
3
4
5
6
7
8
9
10Recursion is a common mathematical and programming concept. This has the benefit of meaning that you can loop through data to reach a result.
The developer should be careful with recursion functions as it can be quite easy to slip into writing a function which never terminates, or one that uses excess amounts of memory or processor power. However, when written correctly recursion can be a very efficient and mathematically-elegant approach to programming.
In the following example, factorial_recursion() is a function that calls itself. We use the x variable as the data, which decrements (-1) every time we recurse. The recursion ends when the condition is not greater than 0 (i.e. when it is 0).
Example
package main
import ("fmt")
func factorial_recursion(x float64) (y float64) {
if x > 0 {
y = x * factorial_recursion(x-1)
} else {
y = 1
}
return
}
func main() {
fmt.Println(factorial_recursion(4))
}
Result:
24
To a new developer it can take some time to work out how exactly this works, best way to find out is by testing and modifying it.