Solution: Hide substring

---

examples/hide-substring/hide_substring.go

package main

import (
    "fmt"
    "strings"
)

func main() {
    input := "0123456789"
    fmt.Println(input)

    // show 4 * characters and then the last 4 characters
    out := "****" + input[len(input)-4:]
    fmt.Println(out)

    // show the first 4 characters and then 4 stars
    out = input[0:4] + "****"
    fmt.Println(out)

    // replace every character, except the last 4 by a *
    out = strings.Repeat("*", len(input)-4) + input[len(input)-4:]
    fmt.Println(out)

    // replace every character, except the first 4 by a *
    out = input[0:4] + strings.Repeat("*", len(input)-4)
    fmt.Println(out)
}