Sorting

Go’s sort package implements sorting for builtins and user-defined types. We’ll look at sorting for builtins first.

package main

import (
    "fmt"
    "sort"
)

func main() {

    // Sort methods are specific to the builtin type
    // here’s an example for strings.
    // Note that sorting is in-place
    // so it changes the given slice and doesn’t return a new one.
    strs := []string{"c", "a", "b"}
    sort.Strings(strs)
    fmt.Println("Strings:", strs)

    // An example of sorting ints.
    ints := []int{7, 2, 4}
    sort.Ints(ints)
    fmt.Println("Ints:   ", ints)

    // We can also use sort to check if a slice is already in sorted order.
    s := sort.IntsAreSorted(ints)
    fmt.Println("Sorted: ", s)
}

Running our program prints the sorted string and int slices and true as the result of our AreSorted test.

$ go run sorting.go
Strings: [a b c]
Ints:    [2 4 7]
Sorted:  true