How to sort Slice of Integers in Golang?

Go – Sort Slice of Integers

To sort a slice of integers in Go programming, use sort package. sort package offers sorting for builtin datatypes and user defined datatypes, through which we can sort a slice of integers.

The syntax to sort a slice of integers intSlice using sort package is

sort.Ints(intSlice)

The sorting happens in-place. Therefore original slice of integers is modified.

By default, the sorting happens in ascending order.

To sort in descending order, we may use sort.Reverse function.

Note that we have to import sort package prior to using sort.Ints function.

Examples

In the following example, we will take a slice of integers in intSlice, and sort them in ascending order using sort.Ints().

example.go

package main

import (
	"fmt"
	"sort"
)

func main() {
	intSlice := []int{5, 3, 4, 1, 2}
	fmt.Println("Before sorting :", intSlice)
	sort.Ints(intSlice)
	fmt.Println("After  sorting :", intSlice)
}

Output

Before sorting : [5 3 4 1 2]
After  sorting : [1 2 3 4 5]

Now, we shall sort this slice of integers in decreasing order, using sort.Reverse function.

example.go

package main

import (
	"fmt"
	"sort"
)

func main() {
	intSlice := []int{5, 3, 4, 1, 2}
	fmt.Println("Before sorting :", intSlice)
	sort.Sort(sort.Reverse(sort.IntSlice(intSlice)))
	fmt.Println("After  sorting :", intSlice)
}

Output

Before sorting : [5 3 4 1 2]
After  sorting : [5 4 3.6.0]

Conclusion

In this Golang Tutorial, we learned how to sort a Slice of Integers in Go programming language using sort package, with the help of example programs.