我使用了一个简单的Java脚本计算器，使用的是HTML和css.但是，当我单击某个按钮时，特定值并未按预期显示.这段代码出了什么问题，我该如何修复它？我是JS的新手，这个问题是从JS，this.currentOperand = this.currentOperand.toString() + number.toString()的appendNumber函数中的这行代码开始的
注意-代码不是我的
class Calculator {
constructor(previousOperandTextElement, currentOperandTextElement) {
this.previousOperandTextElement = previousOperandTextElement;
this.currentOperandTextElement = currentOperandTextElement;
}
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.currentOperand
this.getDisplayNumber(this.currentOperand)
if (this.operation != null) {
this.previousOperandTextElement.innerText = this.previousOperand
`${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()
}) *, *::before, *::after {
box-sizing: border-box;
font-family: Arial Black, sans-serif;
font-weight: normal;
}
body {
padding: 0;
margin: 0;
background: linear-gradient(to right, #00AAFF, #99e016);
}
.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: rgba(255,255,255,.75);
}
.calculator-grid > button:hover {
cursor: pointer;
font-size: 2rem;
border: 1px solid white;
outline: none;
background-color: rgba(255, 255, 255, 0.95);
}
.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: rgba(255,255,255,.75);
font-size: 1.5rem;
}
.output .current-operand {
color: white;
font-size: 2.5rem;
}<!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>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>