app.js

const buttons = document.querySelectorAll('button')
const screenDisplay = document.querySelector('.screen')

let calculation = []
let accumulativeCalculation

function calculate(button){
    const value = button.textContent
    if (value === 'CLEAR'){
        calculation = []
        screenDisplay.textContent = '.'
    } else if (value === '='){
        screenDisplay.textContent = eval(accumulativeCalculation)
    } else {

    calculation.push(value)
    accumulativeCalculation = calculation.join('')
    screenDisplay.textContent = accumulativeCalculation
    }
}

buttons.forEach(button => button.addEventListener('click', () => calculate(button)))