use JakubTheDeveloper\Exchange\Exchange;
use JakubTheDeveloper\Exchange\Currency;
use JakubTheDeveloper\Exchange\ExchangeRate;
use JakubTheDeveloper\Exchange\ExchangeRates;
$euro = new Currency('EUR');
$gbp = new Currency('GBP');
$usd = new Currency('USD');
$yuan = new Currency('RMB');
$exchange = new Exchange(
new ExchangeRates([
new ExchangeRate($euro, $gbp, 0.91, 2), // parameters: source currency, target currency, rate, precision
new ExchangeRate($gbp, $euro, 1.10, 2),
new ExchangeRate($usd, $yuan, 6.82, 4),
new ExchangeRate($yuan, $usd, 0.15, 4),
])
);
$exchange->exchange($euro, $gbp, 5.14); // 4.68
$exchange->exchange($gbp, $euro, 3.27); // 3.60
$exchange->exchange($usd, $yuan, 17.23); // 117.5086
$exchange->exchange($yuan, $usd, 223.46); // 33.519