Go Slice – Get Last Element

In Go, slices are dynamic collections that allow you to access elements by their index. To get the last element of a slice, you use the index len(slice) - 1. However, you must ensure that the slice is not empty to avoid runtime errors.

In this tutorial, we will explore how to get the last element of a slice in Go with practical examples and detailed explanations.

Steps to Get the Last Element of a Slice

Check If Slice Is Empty: Ensure the slice has at least one element to avoid runtime errors.
Access the Last Element: Use the index len(slice) - 1 to retrieve the last element of the slice.
Handle Edge Cases: Return an error or a default value if the slice is empty.

Examples of Getting the Last Element of a Slice

1. Get the Last Element of a Slice of Integers

This example demonstrates how to get the last element of a slice of integers:

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package main

import "fmt"

// Function to get the last element of a slice
func getLast(slice []int) (int, error) {
    if len(slice) == 0 {
        return 0, fmt.Errorf("slice is empty")
    }
    return slice[len(slice)-1], nil
}

func main() {
    // Declare and initialize a slice
    numbers := []int{10, 20, 30, 40, 50}

    // Get the last element
    lastElement, err := getLast(numbers)
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    // Print the last element
    fmt.Println("Last Element:", lastElement)
}

Explanation

Validate Slice: The function checks if the slice is empty and returns an error if true.
Get Last Element: The value at index len(slice) - 1 is retrieved and returned as the last element.
Print Result: The last element is printed in the main function.

Output

2. Get the Last Element of a Slice of Strings

This example demonstrates how to get the last element of a slice of strings:

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package main

import "fmt"

// Function to get the last element of a slice
func getLast(slice []string) (string, error) {
    if len(slice) == 0 {
        return "", fmt.Errorf("slice is empty")
    }
    return slice[len(slice)-1], nil
}

func main() {
    // Declare and initialize a slice
    words := []string{"apple", "banana", "cherry", "date"}

    // Get the last element
    lastElement, err := getLast(words)
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    // Print the last element
    fmt.Println("Last Element:", lastElement)
}

Explanation

Validate Slice: The function checks if the slice is empty and returns an error if true.
Get Last Element: The value at index len(slice) - 1 is retrieved and returned as the last element.
Print Result: The last element is printed in the main function.

Output

Points to Remember

Bounds Checking: Always check if the slice is empty before accessing elements to prevent runtime errors.
Generic Logic: The same logic can be applied to slices of any type, such as integers, strings, or custom structs.
Default Values: When the slice is empty, return a default value (e.g., 0 for integers or an empty string for strings) along with an error.

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How to Get Last Element in Slice in Go