Create a simple calculator in JavaScript, HTML, and CSS, In this JS exercise tutorial, Create a Java Script application to perform a arithmetic operation and create a calculator application using Java Script, HTML, and CSS.
Problem Statement
In this, you have to create a simple calculator using the HTML, CSS, Js functions. First, create an HTML file, use CSS files and use the javascript function so that the function returns a result on the output screen.
Solution
- Create HTML file as xyz.html
- Create two sections of calculator that is for keys and for display answer use div class=” calculator” and div class=” keys“
- Next, create 4 rows for keys use div class=”row” for button use <button value=”7″>7</button> likewise create all buttons.
- Use CSS to style buttons and view of the calculator
- In javascript, to select all the buttons use document.querySelectorAll(‘button’);
- Add eventListener to each button that waits for an event to occur (that is the user clicked mouse or will pressed the keys) using button.addEventListener(‘click’, calculate);
- To perform operation we have created calculate function taking event as a first agrment like this function calculate(event)
- Inside this function, we will Calculate and display the answer use eval() function, (eval() is used to evaluate the function) like this display.value = eval(display.value);
- At last, in order to clear everything on display screen use clickedButtonValue === ‘C’.
JS code to create a simple calculator
<!DOCTYPE html> <html lang="en"> <head> <title>Calculator</title> </head> <body> <div class="calculator"> <input type="text" class="display" disabled> <div class="keys"> <div class="row"> <button value="7">7</button> <button value="8">8</button> <button value="9">9</button> <button value="+" class="operator">+</button> </div> <div class="row"> <button value="4">4</button> <button value="5">5</button> <button value="6">6</button> <button value="-" class="operator">-</button> </div> <div class="row"> <button value="1">1</button> <button value="2">2</button> <button value="3">3</button> <button value="*" class="operator">*</button> </div> <div class="row"> <button value="C" class="operator">C</button> <button value="0">0</button> <button value="/" class="operator">/</button> <button value="=" class="operator">=</button> </div> </div> </div> </body> <style> * { padding: 0; margin: 0; } body { width: 100vw; height: 100vh; overflow: hidden; display: flex; justify-content: center; align-items: center; background-color: #222831; font-family: sans-serif; } .calculator { width: 200px; padding-bottom: 15px; border-radius: 7px; background-color: #000; box-shadow: 5px 8px 8px -2px rgba(0, 0, 0, 0.61); } .display { width: 100%; height: 80px; border: none; box-sizing: border-box; padding: 10px; font-size: 2rem; background-color: #FFC0CB; color: #000; text-align: right; border-top-left-radius: 7px; border-top-right-radius: 7px; } .row { display: flex; justify-content: space-between; } button { width: 50px; height: 50px; border-radius: 50%; border: none; outline: none; font-size: 2rem; background-color: #222; color: #fff; margin: 10px; } button:hover { cursor: pointer; } .operator { background-color: #FFC0CB; color: #000; } </style> <script> const buttons = document.querySelectorAll('button'); const display = document.querySelector('.display'); buttons.forEach(function(button) { button.addEventListener('click', calculate); }); function calculate(event) { const clickedButtonValue = event.target.value; if (clickedButtonValue === '=') { if (display.value !== '') { display.value = eval(display.value); } } else if (clickedButtonValue === 'C') { display.value = ''; } else { display.value += clickedButtonValue; } } </script> </html>
Output
Thus, in this way, we learn How to create a simple Calculator using HTML, CSS, and JavaScript.