Add Element to Slice

Lesson 3 of 21 in Coddy's Slices and Maps in Golang course.

In the last lessons, we discussed that the difference between a slice and an array lies in their size, which becomes evident when checking the length.

For instance, if we define a slice like this:

nums := []int{23, 5, 6}

Our slice has three elements, and checking the length using the len() function gives us 3:

nums := []int{23, 5, 6}
fmt.Println(len(nums)) // 3

If we add elements to the slice and check the size, we will get the new size:

nums := []int{23, 5, 6, 9, 22}
fmt.Println(len(nums)) // 5

On the contrary, an array has a fixed size. For example:

nums := [4]int{23}
fmt.Println(len(nums)) // 4

Even though it has fewer elements than 4, the length remains fixed.

Adding elements to a slice is done using append:

books := []string{"Python", "Rust"}
books = append(books, "Golang")
fmt.Println(books)

Running this gives:

[Python Rust Golang]

In Golang, slices come with built-in functions, and append() is one of them, enabling us to add new elements to an existing slice.

Note that, due to the dynamic size of slices, we cannot use the index to add elements ( books[2] = "Golang" won't work).

Challenge

Easy

Write a program that takes 3 inputs from the user and adds them to the slice named coddy as defined in the given code. Perform the following steps:

Print the length of the slice before adding elements.
Add elements to the slice.
Print the slice and the updated length after adding elements (in different lines).

Try it yourself

package main

import "fmt"

func main() {
    // Get the Input from the user Dont't change this!
    var first, second, third string
	fmt.Scan(&first)
	fmt.Scan(&second)
	fmt.Scan(&third)
	// Define the Slice
    coddy := []string {"SQL","Rust","C#","Golang"}
    // Print the length
    
    // Add element to the Slice
    
    // Print the slice and the updated length

}

All lessons in Slices and Maps in Golang

1Introduction

Introduction

4Maps

Maps Copy a Map Add and Delete Elements Check for a Key Recap Challenge #1

2Slices

Slices vs ArraysAdd Element to SliceSlicing Slicing Ways Reslicing Slice Capacity Max Capacity Iterate Over a Slice Recap Challenge #1

3Slices Behind the Scene

Slice is an Array Slice with Make Copy a Slice Delete an Element Recap Challenge #1 Recap Challenge #2