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), ) }
A Tour of Go If with a short statement
原文：http://www.cnblogs.com/ghgyj/p/4053006.html