How to create calculater using JavaScript
However, we have scientific or sophisticated calculators used to solve complex tasks such as trigonometry functions, degrees, exponential operators, log functions, hyperbolic functions, square root, and so on. In this topic, we will create a calculator program in JavaScript.
<!-- Create a simple Program to build the Calculator in JavaScript using with HTML and CSS web languages. -->
<!DOCTYPE html>
<html >
<head>
<title> JavaScript Calculator </title>
<style>
h1 {
text-align: center;
padding: 23px;
background-color: red;
color: white;
}
#clear{
width: 270px;
border: 3px solid gray;
border-radius: 3px;
padding: 20px;
background-color: red;
}
.formstyle
{
width: 300px;
height: 530px;
margin: auto;
border: 3px solid blue;
border-radius: 5px;
padding: 20px;
}
input
{
width: 20px;
background-color: green;
color: white;
border: 3px solid gray;
border-radius: 5px;
padding: 26px;
margin: 5px;
font-size: 15px;
}
#calc{
width: 250px;
border: 5px solid black;
border-radius: 3px;
padding: 20px;
margin: auto;
}
</style>
</head>
<body>
<h1> Calculator Program in JavaScript </h1>
<div class= "formstyle">
<form name = "form1">
<!-- This input box shows the button pressed by the user in calculator. -->
<input id = "calc" type ="text" name = "answer"> <br> <br>
<!-- Display the calculator button on the screen. -->
<!-- onclick() function display the number prsses by the user. -->
<input type = "button" value = "1" onclick = "form1.answer.value += '1' ">
<input type = "button" value = "2" onclick = "form1.answer.value += '2' ">
<input type = "button" value = "3" onclick = "form1.answer.value += '3' ">
<input type = "button" value = "+" onclick = "form1.answer.value += '+' ">
<br> <br>
<input type = "button" value = "4" onclick = "form1.answer.value += '4' ">
<input type = "button" value = "5" onclick = "form1.answer.value += '5' ">
<input type = "button" value = "6" onclick = "form1.answer.value += '6' ">
<input type = "button" value = "-" onclick = "form1.answer.value += '-' ">
<br> <br>
<input type = "button" value = "7" onclick = "form1.answer.value += '7' ">
<input type = "button" value = "8" onclick = "form1.answer.value += '8' ">
<input type = "button" value = "9" onclick = "form1.answer.value += '9' ">
<input type = "button" value = "*" onclick = "form1.answer.value += '*' ">
<br> <br>
<input type = "button" value = "/" onclick = "form1.answer.value += '/' ">
<input type = "button" value = "0" onclick = "form1.answer.value += '0' ">
<input type = "button" value = "." onclick = "form1.answer.value += '.' ">
<!-- When we click on the '=' button, the onclick() shows the sum results on the calculator screen. -->
<input type = "button" value = "=" onclick = "form1.answer.value = eval(form1.answer.value) ">
<br>
<!-- Display the Cancel button and erase all data entered by the user. -->
<input type = "button" value = "Clear All" onclick = "form1.answer.value = ' ' " id= "clear" >
<br>
</form>
</div>
</body>
</html>
