The pit of the split function inside the strings bag

Regardless of the development language, the split function is often used. Recently discovered the split function in the strings bag has a pit, really live long see.

package mainimport "fmt"import "strings"func main() {    str := ""    v := strings.Split(str, "#")    if len(v)%2 != 0 {        fmt.Printf("v len is [%d]", len(v))    }}

Expect to get the result should be 0, because often read the data field when it will do is not a few tuples of judgment. The actual output is:

v len is [1]

See the implementation of split

 func genSplit(s, sep string, sepSave, n int) []string {    if n == 0 {        return nil    }    if sep == "" {        return explode(s, n)    }    if n < 0 {        n = Count(s, sep) + 1    }    c := sep[0]    start := 0    a := make([]string, n)    na := 0    for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ {        if s[i] == c && (len(sep) == 1 || s[i:i+len(sep)] == sep) {            a[na] = s[start : i+sepSave]            na++            start = i + len(sep)            i += len(sep) - 1        }    }    a[na] = s[start:]    return a[0 : na+1]}

You can see that the last returned slice has at least one value. Pay more attention to details, not to use the inherent concept of new things.