basic calculator using javascript code example
Example 1: a simple javascript calculator
<div class="calculator">
<input type="text" class="calculator-screen" value="" disabled />
<div class="calculator-keys">
<button type="button" class="operator" value="+">+</button>
<button type="button" class="operator" value="-">-</button>
<button type="button" class="operator" value="*">×</button>
<button type="button" class="operator" value="/">÷</button>
<button type="button" value="7">7</button>
<button type="button" value="8">8</button>
<button type="button" value="9">9</button>
<button type="button" value="4">4</button>
<button type="button" value="5">5</button>
<button type="button" value="6">6</button>
<button type="button" value="1">1</button>
<button type="button" value="2">2</button>
<button type="button" value="3">3</button>
<button type="button" value="0">0</button>
<button type="button" class="decimal" value=".">.</button>
<button type="button" class="all-clear" value="all-clear">AC</button>
<button type="button" class="equal-sign operator" value="=">=</button>
</div>
</div>
Example 2: how to create a simple calculator in html
<!DOCTYPE html>
<html lang="en">
<head>
<style>
.contain{
display: flex;
}
#display{
width: 98%;
}
.mathButtons{
width: 100px;
height: 40px;
background-color: rgb(0,0,0,0.3);
color: white;
}
.mathButtons:hover{
background-color: DodgerBlue;
}
#clearButton:hover{
background-color: orangered;
}
#container{
width: 430px;
height: 300px;
}
.buttondigits{
background-color: black;
color: white;
height: 40px;
width: 100px;
}
#clearButton{
width: 100px;
height: 40px;
background-color: rgb(0,0,0,0.3);
font-weight: bold;
}
.buttondigits:hover {
background-color: gray;
}
</style>
<title> standard calculator </title>
<meta charset="utf-8">
<link rel="stylesheet" href="cal.css"/>
</head>
<body>
<div class="container">
<fieldset id="container">
<form name="calculator">
<input type="text" id="display" name="display" readonly>
<br>
<br>
<br>
<div class="contain">
<input class="buttondigits" type="button" value="7" onclick="calculator.display.value += '7'">
<input class="buttondigits" type="button" value="8" onclick="calculator.display.value += '8'">
<input class="buttondigits" type="button" value="9" onclick="calculator.display.value += '9'">
<input class="mathButtons" type="button" value="+" onclick="calculator.display.value += '+'">
</div>
<div class="contain">
<input class="buttondigits" type="button" value="4" onclick="calculator.display.value += '4'">
<input class="buttondigits" type="button" value="5" onclick="calculator.display.value += '5'">
<input class="buttondigits" type="button" value="6" onclick="calculator.display.value += '6'">
<input class="mathButtons" type="button" value="-" onclick="calculator.display.value += '-'">
</div>
<div class="contain">
<input class="buttondigits" type="button" value="1" onclick="calculator.display.value += '1'">
<input class="buttondigits" type="button" value="2" onclick="calculator.display.value += '2'">
<input class="buttondigits" type="button" value="3" onclick="calculator.display.value += '3'">
<input class="mathButtons" type="button" value="*" onclick="calculator.display.value += '*'">
</div>
<div class="contain">
<input id="clearButton" class="button" type="button" value="C" onclick="calculator.display.value = ''">
<input class="buttondigits" type="button" value="0" onclick="calculator.display.value += '0'">
<input class= "mathButtons" type="button" value="=" onclick="calculator.display.value = eval(calculator.display.value)">
<input class="mathButtons" type="button" value="/" onclick="calculator.display.value += '/'">
</div>
</form>
</fieldset>
</div>
</body>
</html>
Example 3: how to make a calculator websiteJS
let add =(...params) => {
let sum = 0;
params.forEach(el =>{
sum = sum + parseInt(el);
})
return sum
}
document.querySelector('.add').addEventListener('click' , function (e) {
const adder = document.querySelector('.addinput').value
const meow = adder.split(',')
let result = add(...meow)
if (isNaN(result)) {
result = 'ENTER A NUMBER'
}
document.querySelector('.result').textContent = result
})
let times =(...params) => {
let multiply = 1;
params.forEach(el =>{
multiply = multiply * el;
})
return multiply
}
document.querySelector('.multiply').addEventListener('click' , function (e) {
const multiplier = document.querySelector('.multiplyinput').value
const moo = multiplier.split(',')
let product = times(...moo)
if (isNaN(product)) {
product = 'ENTER A NUMBER'
}
document.querySelector('.product').textContent = product
})
let subtract =(...params) => {
let diff = 0;
diff = params[0] - params[1]
return diff
}
document.querySelector('.subtract').addEventListener('click' , function (e) {
const subtracter = document.querySelector('.subtractinput').value
const woof = subtracter.split(',')
let diff = subtract(...woof)
if (isNaN(diff)) {
diff = 'ENTER A NUMBER'
}
document.querySelector('.difference').textContent = diff
})
let divide =(...params) => {
let quotient = 0;
quotient = params[0] / params[1]
return quotient
}
document.querySelector('.divide').addEventListener('click' , function (e) {
const divider = document.querySelector('.divideinput').value
const moo2 = divider.split(',')
let quotient = divide(...moo2)
if (isNaN(quotient)) {
quotient = 'ENTER A NUMBER'
}
document.querySelector('.quotient').textContent = quotient
})