Stylish HTML, CSS, and JS Counter: A Visual Delight

We need a counter for a lot of stuff when building web apps whether be it displaying the number of users who visited our site, live views or any other stats. We can easily make one by simply using JS to manipulate the text inside an element that holds the value for the counter but it looks boring.

Now we'll see how can we make a better version of the counter which works like an odometer just using some plain HTML, CSS and JS.

💡

Note to Readers: This article is written with the assumption that you have a basic understanding of HTML, CSS, and JavaScript. We won't cover the fundamentals of these technologies in detail. If you are new to web development or need a refresher on these topics, consider exploring introductory tutorials and resources before diving into this content. although I can assure you I tried to keep it as simple as possible

What the final result looks like

Final result gif

HTML

First, we will set up a basic HTML structure, I have also added some CSS classes to the elements which we'll see later in the CSS part. We'll name the file index.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Counter</title>
        <link rel="stylesheet" href="style.css">
    </head>
    <body>
        <div class="box">
            <div class="counter-container" id="cc">
            </div>
            <div class="button-container" id="bc">
                <input class="button red" type="button" value="backword" id="b">
                <input class="button green" type="button" value="forward" id="f">
            </div>
        </div>
        <script src="counter_script.js"></script>
    </body>
</html>

We have three things(div) to consider here

box - div with a class box that holds two other divs counter-container and button-container
Counter-container - This will be populated using JavaScript later. This will hold the contents of the counter
button container - This will hold the buttons used to increase and decrease the counter

I have also linked a stylesheet and a script to this document which I'll explain later

CSS

Let's make things look pretty

body,html{
    height: 100%;
    overflow: hidden;
    margin: 0px;
}

.box{
    display: flex;
    background-color: rgb(50, 49, 48);
    justify-content: center;
    align-items: center;
    flex-direction: column;
    height: 100%;
}

.counter-container{
    display: flex;
    width: fit-content;
    border: 4px rgb(73, 71, 66) solid;
    overflow: hidden;
    border-radius: 10px;
}

.button-container{
    margin: 10px;
    padding: 10px;
    border-radius: 5px;
    background-color: rgb(171, 166, 159);
}

.button{
    font-family: 'Consolas';
    font-size: 15px;
    border-radius: 10px;
    width: 80px;
}

.green{
    background-color: rgb(159, 227, 159);
}

.red{
    background-color: rgb(227, 136, 111);
}

.outer-container{
    background-color:rgb(189, 200, 201);
    padding-left: 4px;
    height: 70px;
    border: 2px black solid;
}

.number-container{
    font-family: 'Consolas';
    font-size: 60px;
    width: 0.6em;
    transition: transform;
    transition-duration: 0.2s;
}

.number{
    height: 70px;
}

Here we can see all the definitions of CSS classes that we have used in our HTML. I'll explain this CSS in a brief

box - this will be applied to the outermost box and we want its content to be at the center of the screen.
counter-container - This will be applied to the div/container of the counter and its overflow is hidden for a reason which I'll explain later
button-container - This will be applied to the div/container that holds the buttons
green, red - these are just class
body, html - we set the height of this element to 100% so the whole screen is covered
outer-container - This will be applied to the div that holds the divs representing each digit of the number. This div will be later added to the DOM using JS
number-container - This will be applied to individual digit divs that will hold the divs of numbers ranging from 0 to 9. This div will be later added to the DOM using JS
number - this will be applied to the div that holds each number

Don't worry if you find this a little bit confusing you'll understand this later when we talk counter container will be populated using JavaScript

The only thing you need to keep in mind while styling this is the overflow of the counter-container should be hidden as this directly affects the look and functionality of the counter. You need to also maintain the HTML structure as shown above for this to work

JavaScript

I will be explaining this JS code function by function first. Once we know the purpose of each function we will see how we use the functions to get our desired result.

We have three functions

get_number_digits
make_number_containers
counter_setter

get_number_digits

function get_number_digits(number){
    if (number == 0) return 1

    let number_of_digits = 0
    while(number > 0) {
        number = Math.floor(number/10)
        number_of_digits ++
    }
    return number_of_digits
}

This function will return the number of digits in a given number for example if the number is 3432 number of digits will be 4. If the number is 23932 the number of digits will be 5.

make_number_containers

function make_number_containers(number_of_digits) {
    let counter_c = document.getElementById('cc')

    // creating a number container for each digit of the number
    for (let index = number_of_digits; index > 0; index--) {

        // creating outer container and adding the required class
        let outer_c = document.createElement('div')
        outer_c.classList.add('outer-container')

        // creating number container and adding the required class and id
        let num_c = document.createElement("div")
        num_c.classList.add('number-container')
        num_c.id = 'nums' + index

        // adding number div inside number container. one for each from 0-9
        for (let i = 0; i < 10; i++) {
            let num = document.createElement('div')
            num.classList.add('number')
            num.innerText = i
            num_c.appendChild(num)
        }

        outer_c.appendChild(num_c)
        counter_c.appendChild(outer_c)
    }

}

The idea behind this function is that we create an outer-container for each digit of a number inside the counter. Inside it, we create a number-container that has 10 divs. Each div will represent a number from 0-9.

You will understand it better when you see this picture.

Let us assume the number is 0 so the number of digits will be 1 in that case only one container will be created. For the demonstration purpose, I have removed the overflow: hidden property of the counter-container class. This will give you a better perspective of things and now you will also understand the purpose of making the overflow hidden of counter-container.

HTML for the above image will look like this

<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Counter</title>
        <link rel="stylesheet" href="style.css">
    </head>
    <body>
        <div class="box">
            <div class="counter-container" id="cc">
                <div class="outer-container">
                    <div class="number-container" id="nums1" style="transform: translateY(0px);">
                        <div class="number">0</div>
                        <div class="number">1</div>
                        <div class="number">2</div>
                        <div class="number">3</div>
                        <div class="number">4</div>
                        <div class="number">5</div>
                        <div class="number">6</div>
                        <div class="number">7</div>
                        <div class="number">8</div>
                        <div class="number">9</div>
                    </div>
                </div>
            </div>
        </div>
        <script src="counter_script.js"></script>
    </body>
</html>

Here we have only one digit so only one container is created. If we set the overflow: hidden property of the counter-container class as intended we will get the following result

counter_setter

function counter_setter(number,salt) {
    for (let index = 1; index <= number_of_digits; index++) {
        // getting the correct number container
        let id = 'nums' + index
        let div = document.getElementById(id)

        // Geting the last digit of number
        const digit = (number % 10); 
        let value = Math.floor(SLIDE_CONST * digit)
        value = Math.round(value + (salt * digit)) // adding salt to the value

        // updating the translate value of the div after 200ms
        setTimeout(() => { div.style.transform = `translateY(-${value}px)` }, 200)
        number = Math.floor(number / 10); // Remove the last digit
    }
}

Now we have a better picture of how the number divs are stacked on top of each other and because the overflow is hidden we can only see one number at a time. Now to display any number we just have to slide the number container up or down.

We calculate the number of pixels we need to slide the number container using this simple formula

silde_value = slide_constant x digit

where slide constant is the height of the div containing each number. In our case height is 70px. Suppose we have to display the number 7. Using the above formula we have to slide the container that holds the stacked divs of number exactly 490px.

The basic idea of this function is that we simply go through each digit of the given number access its number container and slide it depending on the value of the digit

💡

The salt variable in the function is added because sometimes due to sub-pixel rendering and some other factors even when we calculate the sliding value correctly using the above formula, the sliding value will be off by a pixel or two which becomes noticeable as we move to a greater number. For example, if we have the slide constant as 50px and we want to display the number 1 we would assume that the slide value should be 100 but for some reason, it might be 101. Similarly, if we want to display the number 2 it can be 152. so if we want to display the number 9 it will be 509, which is off by 9 pixels and very noticeable. The salt is the value that helps balance this anomaly. Even I don't know the exact reason why it happens. It happens for some fonts and font sizes and for some, it does not.

So now we just have to put all these functions together. Here is what the final js code will look like

function get_number_digits(number){
    if (number == 0) return 1

    let number_of_digits = 0
    while(number > 0) {
        number = Math.floor(number/10)
        number_of_digits ++
    }
    return number_of_digits
}


function make_number_containers(number_of_digits) {
    let counter_c = document.getElementById('cc')

    // creating a number container for each digit of the number
    for (let index = number_of_digits; index > 0; index--) {

        // creating outer container and adding the required class and id
        let outer_c = document.createElement('div')
        outer_c.classList.add('outer-container')

        // creating number container and adding the required class
        let num_c = document.createElement("div")
        num_c.classList.add('number-container')
        num_c.id = 'nums' + index

        // adding number div inside number container. one for each from 0-9
        for (let i = 0; i < 10; i++) {
            let num = document.createElement('div')
            num.classList.add('number')
            num.innerText = i
            num_c.appendChild(num)
        }

        outer_c.appendChild(num_c)
        counter_c.appendChild(outer_c)
    }

}

function counter_setter(number,salt) {
    for (let index = 1; index <= number_of_digits; index++) {
        // getting the correct number container
        let id = 'nums' + index
        let div = document.getElementById(id)

        // Geting the last digit of number
        const digit = (number % 10); 
        let value = Math.floor(SLIDE_CONST * digit)
        value = Math.round(value + (salt * digit)) // adding salt to the value

        // updating the translate value of the div after 200ms
        setTimeout(() => { div.style.transform = `translateY(-${value}px)` }, 200)
        number = Math.floor(number / 10); // Remove the last digit
    }
}

const SLIDE_CONST = 70
let number_counter = 1238
let salt = 0
let number_of_digits = get_number_digits(number_counter)
let btn_c = document.getElementById('bc')


make_number_containers(number_of_digits)
counter_setter(number_counter, salt)

btn_c.addEventListener('click',(event)=>{
    if (event.target.tagName == 'INPUT'){
        if(event.target.id == "f") number_counter ++
        if(event.target.id == "b") number_counter --
        console.log(number_counter);
        counter_setter(number_counter, salt)
    }
})

get_number_digits(number): This function calculates the number of digits in a given number. It returns 1 if the number is 0 and counts the digits using a while loop for positive numbers.
make_number_containers(number_of_digits): This function creates a set of HTML containers for displaying individual digits of a number. It appends these containers to an element with the id 'cc'.
counter_setter(number, salt): This function updates the display of the individual digit containers to simulate a sliding effect. It takes the number and salt as parameters and adjusts the position of each digit container based on these values.
Constants and variables: They define a constant SLIDE_CONST with a value of 70 and initializes variables number_counter, salt, and number_of_digits. The number_counter represents the current number, while salt is used for adjusting the sliding effect. The number_of_digits is calculated using the get_number_digits function.
btn_c is assigned a reference to an HTML element with the id 'bc', which is expected to be a button.
The code calls make_number_containers(number_of_digits) to create the initial digit containers based on the number of digits in number_counter.
It calls counter_setter(number_counter, salt) to set the initial display of the digit containers based on the number_counter and salt.
An event listener is added to btn_c to listen for click events on its child elements. When a click occurs on an input element inside btn_c, it checks the element's id attribute. If it's "f," it increments number_counter; if it's "b," it decrements number_counter and then logs the updated value to the console. Finally, it calls counter_setter to update the display based on the new number_counter value.

Overall, this code creates a visual representation of a number with sliding digits and allows the user to increment or decrement the displayed number using buttons. The sliding effect is controlled by the counter_setter function and the number of digits in the displayed number is dynamically determined by get_number_digits.

Here's how it looks in action under the hood

Access the code from GitHub repository

If you have reached till here thanks for reading and I hope it helped you in some way. This was my first blog and I hope you guys like it. If you have any suggestions/tips/corrections please feel free to write it down in the comments section.

Happy coding!!!

Cool looking counter in plain HTML,CSS and JS

Table of contents

What the final result looks like

HTML

CSS

JavaScript

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Palash Dhavle

Palash Dhavle