A Tour of Go If with a short statement

Like for, the if statement can start with a short statement to execute before the condition.

Variables declared by the statement are only in scope until the end of the if.

(Try using v in the last return statement.)

package main  

import (
    "fmt"
    "math"
)

func pow(x, n , lim float64) float64 {
    if v := math.Pow(x,n); v < lim {
        return v
    }
    return lim
}

func main() {
    fmt.Println(
            pow(3, 2, 10),
            pow(3, 3, 20),
        )
}