Slices in Golang: Usage and examples

This article explains how to work with slices in Golang, including how to declare, access, and manipulate slices—a flexible way to handle arrays more efficiently in Go.

In Golang, slices are a special type of array that allows you to work with portions of an array without copying them. Slices are more flexible and easier to manage compared to traditional arrays, especially when dealing with dynamic data.

Golang Code

package main

import "fmt"

func main() {
    // Declare an initial array
    arr := [5]int{1, 2, 3, 4, 5}

    // Create a slice from the array
    slice := arr[1:4]

    // Print the elements of the slice
    fmt.Println("Slice:", slice)

    // Modify an element in the slice
    slice[0] = 10

    // Print the original array after modifying the slice
    fmt.Println("Original array:", arr)

    // Append an element to the slice using append
    slice = append(slice, 6)

    // Print the slice after appending
    fmt.Println("Slice after append:", slice)
}

Detailed explanation:

1. arr := [5]int{1, 2, 3, 4, 5}: Creates an array with 5 elements.
2. slice := arr[1:4]: Creates a slice from the array arr, taking elements from index 1 to 3 (excluding index 4).
3. fmt.Println("Slice:", slice): Prints the elements of the slice.
4. slice[0] = 10: Modifies the first element of the slice.
5. fmt.Println("Original array:", arr): Prints the original array to show that the slice shares memory with the array.
6. slice = append(slice, 6): Appends a new element to the slice using the append function.
7. fmt.Println("Slice after append:", slice): Prints the slice after appending the new element.

Tips:

• Slices share memory with the original array, so modifying the slice affects the array as well.
• When using append, if the slice does not have enough memory, a new array will be created to store the data.