script.js

const currencyEl_one = document.getElementById('currency-one');
const amountEl_one = document.getElementById('amount-one');
const currencyEl_two = document.getElementById('currency-two');
const amountEl_two = document.getElementById('amount-two');

const rateEl = document.getElementById('rate');
const swap = document.getElementById('swap');


function calculate() {
    const currency_one = currencyEl_one.value;
    const currency_two = currencyEl_two.value;

    fetch(`https://api.exchangerate-api.com/v4/latest/${currency_one}`)
    .then(results => results.json())
    .then(data => {
        const rate = data.rates[currency_two];

        rateEl.innerText = `1 ${currency_one} = ${rate.toFixed(3)} ${currency_two}`;


        amountEl_two.value = (amountEl_one.value * rate).toFixed(2);
    });
}

currencyEl_one.addEventListener('change', calculate);
amountEl_one.addEventListener('input', calculate);
currencyEl_two.addEventListener('change', calculate);
amountEl_two.addEventListener('input', calculate);

swap.addEventListener('click', () => {
    const temp = currencyEl_one.value;
    currencyEl_one.value = currencyEl_two.value;
    currencyEl_two.value = temp;

    calculate();

})

calculate();