为什么在自身上拆分字符串会返回一个长度为2的空切片？

Question

I'm writing a program where I might end up splitting a string on itself. The string is a URL and I want to split on the slash. I want to do different things based on the URL string.

I'm more curious about why strings.Split returns that unexpected slice. I tried doing this in Python and noticed it also returns a list with a length of two. The intuitive thing for me seems to return an empty list (slice/array). Is there a good reason why two empty strings are returned instead?

package main

import (
    "fmt"
    "strings"
)

func main() {
    fmt.Println(strings.Split("/", "/"))
    fmt.Println("len:", len(strings.Split("/", "/")))
}

// Prints this
[ ]
len: 2

http://play.golang.org/p/-lYrmAKOMR

Answer 1

As I understand it, the split function returns everything before the / (which is nothing) in the first item, and everything after the / (also nothing) in the second item. Hence, two empty strings. As for why you ever get empty strings, it's so that split() can basically be the opposite of join, as explained here:

Why are empty strings returned in split() results?