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Tip Calculator Using HTML, CSS and JavaScript

Introduction :

The Tip Calculator comprises three main components:

  1. HTML (HyperText Markup Language): Defines the structure and content of the web page.
  2. CSS (Cascading Style Sheets): Provides styling to enhance the visual presentation.
  3. JavaScript: Adds interactivity and logic to perform calculations.

Structure

HTML

The HTML file outlines the skeleton of the Tip Calculator. It includes a form where users can input their bill amount and desired tip percentage, and a button to trigger the calculation. The calculated total is then displayed on the same page.

  • The <head> section includes meta tags for character encoding, compatibility, and responsiveness, and links the CSS file for styling.
  • The <body> contains a <div> with a class of container which holds all the interactive elements including:
    • An <h1> for the title.
    • Paragraph <p> for instructions.
    • Labels and input fields for entering the bill amount and tip percentage.
    • A button to trigger the calculation.
    • A span element to display the total amount.

CSS

The CSS file styles the calculator to make it visually appealing and user-friendly.

  • The body is styled with a light background and a specific font.
  • The .container class gives a centered, card-like appearance with padding, a shadow effect, and rounded corners.
  • Inputs and buttons are styled for uniformity, with padding, borders, and hover effects to enhance user interaction.
  • The total span is emphasized with larger, bold text.

JavaScript Logic

The JavaScript file (app.js) provides the core functionality of the Tip Calculator, handling user inputs and performing the necessary calculations.

  • Variable Declarations:

    • btnEl: References the “Calculate” button.
    • billInput: References the input field for the bill amount.
    • tipInput: References the input field for the tip percentage.
    • totalSpan: References the span element where the total amount is displayed.
  • Function calculateTotal:

    • Retrieves the values entered by the user for the bill amount and tip percentage.
    • Computes the total amount by adding the calculated tip to the bill amount. The formula used is billValue * (1 + tipValue / 100).
    • Updates the totalSpan with the calculated total, formatted to two decimal places.
  • Event Listener:

    • Adds a click event listener to the “Calculate” button, which triggers the calculateTotal function when the button is clicked.

Purpose of Functions

  • calculateTotal Function:
    • This function is crucial for the application’s functionality. It processes the user input, performs the arithmetic required to calculate the total amount including the tip, and updates the user interface with the result.
    • It ensures that the total is displayed in a user-friendly format with two decimal places, making the application both practical and easy to use.

By combining these components, the Tip Calculator provides a seamless and interactive experience for users needing to quickly compute the total amount including a tip based on their bill. This project serves as an excellent example of integrating HTML, CSS, and JavaScript to build a functional web application.

SOURCE CODE:

HTML (index.html)

				
					<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Tip Calculator</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div class="container">
        <h1>Tip Calculator</h1>
        <p>Enter the bill amount and tip percentage to calculate the total.</p><div class='code-block code-block-5' style='margin: 8px 0; clear: both;'> <script type="litespeed/javascript" data-src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-2145094925886663"
     crossorigin="anonymous"></script> <ins class="adsbygoogle"
     style="display:block; text-align:center;"
     data-ad-layout="in-article"
     data-ad-format="fluid"
     data-ad-client="ca-pub-2145094925886663"
     data-ad-slot="3349828668"></ins> <script type="litespeed/javascript">(adsbygoogle=window.adsbygoogle||[]).push({})</script></div>

        <label for="bill">Bill amount:</label>
        <input type="number" id="bill">
        <br/>
        <label for="tip">Tip percentage:</label>
        <input type="number" id="tip">
        <br/>
        <button id="calculate">Calculate</button>
        <br/>
        <label for="total">Total:</label>
        <span id="total"></span>

    </div> <script type="litespeed/javascript" data-src="app.js"></script> <script data-no-optimize="1">!function(t,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):(t="undefined"!=typeof globalThis?globalThis:t||self).LazyLoad=e()}(this,function(){"use strict";function e(){return(e=Object.assign||function(t){for(var e=1;e<arguments.length;e++){var n,a=arguments[e];for(n in a)Object.prototype.hasOwnProperty.call(a,n)&&(t[n]=a[n])}return t}).apply(this,arguments)}function i(t){return e({},it,t)}function o(t,e){var n,a="LazyLoad::Initialized",i=new t(e);try{n=new CustomEvent(a,{detail:{instance:i}})}catch(t){(n=document.createEvent("CustomEvent")).initCustomEvent(a,!1,!1,{instance:i})}window.dispatchEvent(n)}function l(t,e){return t.getAttribute(gt+e)}function c(t){return l(t,bt)}function s(t,e){return function(t,e,n){e=gt+e;null!==n?t.setAttribute(e,n):t.removeAttribute(e)}(t,bt,e)}function r(t){return s(t,null),0}function u(t){return null===c(t)}function d(t){return c(t)===vt}function f(t,e,n,a){t&&(void 0===a?void 0===n?t(e):t(e,n):t(e,n,a))}function _(t,e){nt?t.classList.add(e):t.className+=(t.className?" 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</html>
				
			

CSS (style.css)

				
					* {
    box-sizing: border-box;
}

body {
    background-color: #f2f2f2;
    font-family: "Helvetica", sans-serif;
}

.container {
    background-color: white;
    max-width: 600px;
    margin: 100px auto;
    padding: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
    border-radius: 10px;
}

h1 {
    margin-top: 0;
    text-align: center;
}

input {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin: 10px 0;
    width: 100%;
}

button {
    background-color: #6c7bb4;
    color: white;
    padding: 10px;
    border: none;
    cursor: pointer;
    margin: 10px 0;
    width: 100%;
    font-size: 18px;
    text-transform: uppercase;
    transition: background-color 0.2s ease;
}

button:hover {
    background-color: #45a049;
}

#total {
    font-size: 24px;
    font-weight: bold;
    margin-top: 10px;
}
				
			

JavaScript (app.js)

				
					
const btnEl = document.getElementById("calculate");
const billInput = document.getElementById("bill");
const tipInput = document.getElementById("tip");
const totalSpan = document.getElementById("total");

function calculateTotal() {
    const billValue = billInput.value;
    const tipValue = tipInput.value;
    const totalValue = billValue * (1 + tipValue / 100);
    totalSpan.innerText = totalValue.toFixed(2);
}

btnEl.addEventListener("click", calculateTotal);
				
			

OUTPUT :

OUTPUT