script.js

//https://app.exchangerate-api.com

const currencySelectOne = document.querySelector('#select-currency-one');

const amountInputOne = document.querySelector('#amount-one-input');

const currencySelectTwo = document.querySelector('#select-currency-two');

const amountInputTwo = document.querySelector('#amount-two-input');

const rate = document.querySelector('#div-message-rate');

const btnSwap = document.querySelector('#btn-swap');

currencySelectOne.addEventListener('change', calculateRate);
currencySelectTwo.addEventListener('change', calculateRate);

amountInputOne.addEventListener('input', calculateRate);
amountInputTwo.addEventListener('input', calculateRate);

btnSwap.addEventListener('click', function(){
  const tempValue = currencySelectOne.value;
  currencySelectOne.value = currencySelectTwo.value;
  currencySelectTwo.value = tempValue;
  calculateRate();
});

function calculateRate(){
  const currencyOne = currencySelectOne.value;  
  const currencyTwo = currencySelectTwo.value;

  
  fetch(`https://open.er-api.com/v6/latest/${currencyOne}`)
  .then((res)=> res.json())
  .then((data) => {

 
    const rateData = data.rates[currencyTwo];
    
    rate.innerHTML = ` 1 ${currencyOne} = ${rateData} ${currencyTwo}`;

    amountInputTwo.value = (amountInputOne.value * rateData).toFixed(2);
  });


}

calculateRate();