main.go

package main

import (
  "fmt"
)

func main() {
  s := [][]string{
    {"a", "b", "c"},
    {"d", "e", "f"},
  }
  fmt.Printf("s: %v\n", s)
  fmt.Printf("len(s): %v\n", len(s))
  fmt.Printf("s[0]: %v\n", s[0])
  fmt.Printf("len(s[0]): %v\n", len(s[0]))
}

output

[dsont@dsont-pc forky]$ go run main.go
s: [[a b c] [d e f]]
len(s): 2
s[0]: [a b c]
len(s[0]): 3