func Replace(s, old, new string, n int) string
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
}
// Output:
// oinky oinky oink
// moo moo moo