Golang : How to reverse slice or array elements order




In this short tutorial, we will learn how to reverse the elements order inside a slice or array. Taking the example from a previous tutorial on how to reverse elements order in a map, we will reverse the elements order by

 1. calculating the total length of the slice.

 2. deduct 1 position. 

 3. then deduct the current element position to get the last element.

 4. finally, append the last element into a new slice with reversed order.

Here you go!


 package main

 import "fmt"

 func main() {

 cities := [...]string{"New York", "Beijing", "Bangkok", "Adelaide", "Tokyo", "Seoul", "Zurich", "Seattle"}

 fmt.Println("Before : ", cities)

 reversed := []string{}

 // reverse order
 // and append into new slice
 for i := range cities {
 n := cities[len(cities)-1-i]
 //fmt.Println(n) -- sanity check
 reversed = append(reversed, n)
 }

 fmt.Println("After : ", reversed)

 }

Output :

Before : [New York Beijing Bangkok Adelaide Tokyo Seoul Zurich Seattle]

After : [Seattle Zurich Seoul Tokyo Adelaide Bangkok Beijing New York]

  See also : Golang : How to reverse elements order in map ?





By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


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