To design a web application for a standard calculator with minimum five operations.
Clone the github repository and create Django admin interface.
Change settings.py file to allow request from all hosts.
Use CSS for creating attractive colors.
Write JavaScript program for implementing five different operations.
Validate the HTML and CSS code.
Publish the website in the given URL.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Calculator</title>
<link href="styles.css" rel="stylesheet">
<script src="script.js" defer></script>
</head>
<body>
<div class="calculator-grid">
<div class="output">
<div data-previous-operand class="previous-operand"></div>
<div data-current-operand class="current-operand"></div>
</div>
<button data-all-clear class="span-two">AC</button>
<button data-delete>DEL</button>
<button data-operation>÷</button>
<button data-number>1</button>
<button data-number>2</button>
<button data-number>3</button>
<button data-operation>*</button>
<button data-number>4</button>
<button data-number>5</button>
<button data-number>6</button>
<button data-operation>+</button>
<button data-number>7</button>
<button data-number>8</button>
<button data-number>9</button>
<button data-operation>-</button>
<button data-number>.</button>
<button data-number>0</button>
<button data-equals class="span-two">=</button>
</div>
</body>
</html>
<script>
class Calculator {
constructor(previousOperandTextElement, currentOperandTextElement) {
this.previousOperandTextElement = previousOperandTextElement
this.currentOperandTextElement = currentOperandTextElement
this.clear()
}
clear() {
this.currentOperand = ''
this.previousOperand = ''
this.operation = undefined
}
delete() {
this.currentOperand = this.currentOperand.toString().slice(0, -1)
}
appendNumber(number) {
if (number === '.' && this.currentOperand.includes('.')) return
this.currentOperand = this.currentOperand.toString() + number.toString()
}
chooseOperation(operation) {
if (this.currentOperand === '') return
if (this.previousOperand !== '') {
this.compute()
}
this.operation = operation
this.previousOperand = this.currentOperand
this.currentOperand = ''
}
compute() {
let computation
const prev = parseFloat(this.previousOperand)
const current = parseFloat(this.currentOperand)
if (isNaN(prev) || isNaN(current)) return
switch (this.operation) {
case '+':
computation = prev + current
break
case '-':
computation = prev - current
break
case '*':
computation = prev * current
break
case '÷':
computation = prev / current
break
default:
return
}
this.currentOperand = computation
this.operation = undefined
this.previousOperand = ''
}
getDisplayNumber(number) {
const stringNumber = number.toString()
const integerDigits = parseFloat(stringNumber.split('.')[0])
const decimalDigits = stringNumber.split('.')[1]
let integerDisplay
if (isNaN(integerDigits)) {
integerDisplay = ''
} else {
integerDisplay = integerDigits.toLocaleString('en', { maximumFractionDigits: 0 })
}
if (decimalDigits != null) {
return `${integerDisplay}.${decimalDigits}`
} else {
return integerDisplay
}
}
updateDisplay() {
this.currentOperandTextElement.innerText =
this.getDisplayNumber(this.currentOperand)
if (this.operation != null) {
this.previousOperandTextElement.innerText =
`${this.getDisplayNumber(this.previousOperand)} ${this.operation}`
} else {
this.previousOperandTextElement.innerText = ''
}
}
}
const numberButtons = document.querySelectorAll('[data-number]')
const operationButtons = document.querySelectorAll('[data-operation]')
const equalsButton = document.querySelector('[data-equals]')
const deleteButton = document.querySelector('[data-delete]')
const allClearButton = document.querySelector('[data-all-clear]')
const previousOperandTextElement = document.querySelector('[data-previous-operand]')
const currentOperandTextElement = document.querySelector('[data-current-operand]')
const calculator = new Calculator(previousOperandTextElement, currentOperandTextElement)
numberButtons.forEach(button => {
button.addEventListener('click', () => {
calculator.appendNumber(button.innerText)
calculator.updateDisplay()
})
})
operationButtons.forEach(button => {
button.addEventListener('click', () => {
calculator.chooseOperation(button.innerText)
calculator.updateDisplay()
})
})
equalsButton.addEventListener('click', button => {
calculator.compute()
calculator.updateDisplay()
})
allClearButton.addEventListener('click', button => {
calculator.clear()
calculator.updateDisplay()
})
deleteButton.addEventListener('click', button => {
calculator.delete()
calculator.updateDisplay()
})
</script>
<style>
*, *::before, *::after {
box-sizing: border-box;
font-family: Gotham Rounded, sans-serif;
font-weight: normal;
}
body {
padding: 0;
margin: 0;
background:(to right,lightsteelblue,lemonchiffon);
}
.calculator-grid {
display: grid;
justify-content: center;
align-content: center;
min-height: 100vh;
grid-template-columns: repeat(4, 100px);
grid-template-rows: minmax(120px, auto) repeat(5, 100px);
}
.calculator-grid > button {
cursor: pointer;
font-size: 2rem;
border: 1px solid white;
outline: none;
background-color: lightgrey;
}
.calculator-grid > button:hover {
background-color:lightyellow;
}
.span-two {
grid-column: span 2;
}
.output {
grid-column: 1 / -1;
background-color: rgba(0, 0, 0, .75);
display: flex;
align-items: flex-end;
justify-content: space-around;
flex-direction: column;
padding: 10px;
word-wrap: break-word;
word-break: break-all;
}
.output .previous-operand {
color:royalblue;
font-size: 1.5rem;
}
.output .current-operand {
color: white;
font-size: 2.5rem;
}
</style>
The program for designing a standard calculator using HTML and CSS is executed successfully.
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