Javascript计算器不工作-错误消息为'；类别'；保留

我是Javascript新手，我发现很难创建一个工作的计算器，每当我点击计算器按钮时，我都没有收到任何响应，我也会收到错误消息“error:Parsing error:the keyword'class'is reserved class calculator”“如果你能帮我这样的新手，我将不胜感激。”。{ JSLint（2）

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要解决您的问题，请建立一个简单而简短的示例来说明它，而不是完整的150行代码…如果您真的希望得到答案，您从哪里得到这个错误？JSLint还是您的浏览器？哪个浏览器？抱歉，代码太长了，这是我的第一篇文章…错误在代码的开头，我的浏览器是Chrome。

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()
})