// powerful interface to sequences than arrays.

​

package main

​

import "fmt"

​

func main() {

​

    // Unlike arrays, slices are typed only by the

    // elements they contain (not the number of elements).

    // To create an empty slice with non-zero length, use

    // the builtin `make`. Here we make a slice of

    // `string`s of length `3` (initially zero-valued).

    s := make([]string, 3)

    fmt.Println("emp:", s)

​

    // We can set and get just like with arrays.

    s[0] = "a"

    s[1] = "b"

    s[2] = "c"

    fmt.Println("set:", s)

    fmt.Println("get:", s[2])

​

    // `len` returns the length of the slice as expected.

    fmt.Println("len:", len(s))

​

    // In addition to these basic operations, slices

    // support several more that make them richer than

    // arrays. One is the builtin `append`, which

    // returns a slice containing one or more new values.

    // Note that we need to accept a return value from

    // append as we may get a new slice value.

    s = append(s, "d")

    s = append(s, "e", "f")

    fmt.Println("apd:", s)

​

    // Slices can also be `copy`'d. Here we create an

    // empty slice `c` of the same length as `s` and copy

    // into `c` from `s`.

    c := make([]string, len(s))

    copy(c, s)

    fmt.Println("cpy:", c)

​

    // Slices support a "slice" operator with the syntax

    // `slice[low:high]`. For example, this gets a slice

    // of the elements `s[2]`, `s[3]`, and `s[4]`.

    l := s[2:5]

    fmt.Println("sl1:", l)

​

    // This slices up to (but excluding) `s[5]`.

    l = s[:5]

    fmt.Println("sl2:", l)

​

    // And this slices up from (and including) `s[2]`.

    l = s[2:]

    fmt.Println("sl3:", l)

​

    // We can declare and initialize a variable for slice

    // in a single line as well.

    t := []string{"g", "h", "i"}

    fmt.Println("dcl:", t)

​

    // Slices can be composed into multi-dimensional data

    // structures. The length of the inner slices can

    // vary, unlike with multi-dimensional arrays.

    twoD := make([][]int, 3)

    for i := 0; i < 3; i++ {

        innerLen := i + 1

        twoD[i] = make([]int, innerLen)

        for j := 0; j < innerLen; j++ {

            twoD[i][j] = i + j

        }

    }

    fmt.Println("2d: ", twoD)

}

​