原生JS实现简单的汇率转换问题
html代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <meta http-equiv="X-UA-Compatible" content="ie=edge" /> <title>Exchange Rate Calculator</title>
    <link rel="stylesheet" href="style.css" />
</head>
<body>
<img src="money.png" alt="" class="money-img" />
<h1>Exchange Rate Calculator</h1>
<p>Choose the currency and the amounts to get the exchange rate</p>
<div class="container">
    <div class="currency">
        <select id="currency-one">
            <option value="AED">AED</option>
            <option value="ARS">ARS</option>
            <option value="AUD">AUD</option>
            <option value="BGN">BGN</option>
            <option value="BRL">BRL</option>
            <option value="BSD">BSD</option>
            <option value="CAD">CAD</option>
            <option value="CHF">CHF</option>
            <option value="CLP">CLP</option>
            <option value="CNY">CNY</option>
            <option value="COP">COP</option>
            <option value="CZK">CZK</option>
            <option value="DKK">DKK</option>
            <option value="DOP">DOP</option>
            <option value="EGP">EGP</option>
            <option value="EUR">EUR</option>
            <option value="FJD">FJD</option>
            <option value="GBP">GBP</option>
            <option value="GTQ">GTQ</option>
            <option value="HKD">HKD</option>
            <option value="HRK">HRK</option>
            <option value="HUF">HUF</option>
            <option value="IDR">IDR</option>
            <option value="ILS">ILS</option>
            <option value="INR">INR</option>
            <option value="ISK">ISK</option>
            <option value="JPY">JPY</option>
            <option value="KRW">KRW</option>
            <option value="KZT">KZT</option>
            <option value="MXN">MXN</option>
            <option value="MYR">MYR</option>
            <option value="NOK">NOK</option>
            <option value="NZD">NZD</option>
            <option value="PAB">PAB</option>
            <option value="PEN">PEN</option>
            <option value="PHP">PHP</option>
            <option value="PKR">PKR</option>
            <option value="PLN">PLN</option>
            <option value="PYG">PYG</option>
            <option value="RON">RON</option>
            <option value="RUB">RUB</option>
            <option value="SAR">SAR</option>
            <option value="SEK">SEK</option>
            <option value="SGD">SGD</option>
            <option value="THB">THB</option>
            <option value="TRY">TRY</option>
            <option value="TWD">TWD</option>
            <option value="UAH">UAH</option>
            <option value="USD" selected>USD</option>
            <option value="UYU">UYU</option>
            <option value="VND">VND</option>
            <option value="ZAR">ZAR</option>
        </select>
        <input type="number" id="amount-one" placeholder="0" value="1" />
    </div>
    <div class="swap-rate-container">
        <button class="btn" id="swap">
            Swap
        </button>
        <div class="rate" id="rate"></div>
    </div>
    <div class="currency">
        <select id="currency-two">
            <option value="AED">AED</option>
            <option value="ARS">ARS</option>
            <option value="AUD">AUD</option>
            <option value="BGN">BGN</option>
            <option value="BRL">BRL</option>
            <option value="BSD">BSD</option>
            <option value="CAD">CAD</option>
            <option value="CHF">CHF</option>
            <option value="CLP">CLP</option>
            <option value="CNY">CNY</option>
            <option value="COP">COP</option>
            <option value="CZK">CZK</option>
            <option value="DKK">DKK</option>
            <option value="DOP">DOP</option>
            <option value="EGP">EGP</option>
            <option value="EUR" selected>EUR</option>
            <option value="FJD">FJD</option>
            <option value="GBP">GBP</option>
            <option value="GTQ">GTQ</option>
            <option value="HKD">HKD</option>
            <option value="HRK">HRK</option>
            <option value="HUF">HUF</option>
            <option value="IDR">IDR</option>
            <option value="ILS">ILS</option>
            <option value="INR">INR</option>
            <option value="ISK">ISK</option>
            <option value="JPY">JPY</option>
            <option value="KRW">KRW</option>
            <option value="KZT">KZT</option>
            <option value="MXN">MXN</option>
            <option value="MYR">MYR</option>
            <option value="NOK">NOK</option>
            <option value="NZD">NZD</option>
            <option value="PAB">PAB</option>
            <option value="PEN">PEN</option>
            <option value="PHP">PHP</option>
            <option value="PKR">PKR</option>
            <option value="PLN">PLN</option>
            <option value="PYG">PYG</option>
            <option value="RON">RON</option>
            <option value="RUB">RUB</option>
            <option value="SAR">SAR</option>
            <option value="SEK">SEK</option>
            <option value="SGD">SGD</option>
            <option value="THB">THB</option>
            <option value="TRY">TRY</option>
            <option value="TWD">TWD</option>
            <option value="UAH">UAH</option>
            <option value="USD">USD</option>
            <option value="UYU">UYU</option>
            <option value="VND">VND</option>
            <option value="ZAR">ZAR</option>
        </select>
        <input type="number" id="amount-two" placeholder="0" /> </div>
</div>
<script src="script.js"></script>
</body>
</html>
css代码
:root {
    --primary-color: #5fbaa7;
}
*	{
    box-sizing: border-box;
}
body {
    background-color: #f4f4f4;
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 0;
    padding: 20px;
}
h1 {
    color: var(--primary-color);
}
p	{
    text-align: center;
}
.btn {
    color: #fff;
    background: var(--primary-color);
    cursor: pointer;
    border-radius: 5px;
    font-size: 12px;
    padding: 5px 12px;
}
.money-img {
    width: 150px;
}
.currency {
    padding: 40px 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.currency select {
    padding: 10px 20px 10px 10px;
    -moz-appearance: none;
    -webkit-appearance: none;
    appearance: none;
    border: 1px solid #dedede;
    font-size: 16px;
    background: transparent;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2229 2.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%20000002%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-5%200-9.3%201.8-12.9%205.4A17.6%2017.6%200%200%200%200%2082.2c0%205%201.8%209.3%205.4%2012.9l128%20127.9c3.6%203.6%207.8%205.4%2012.8%205.4s9.2-1.8%2012.8-5.4L287%2095c3.5-3.5%205.4-7.8%205.4-12.8%200-5-1.9-9.2-5.5-12.8z%22%2F%3E%3C%2Fsvg%3E');
    background-position: right 10px top 50%, 0, 0;
    background-size: 12px auto, 100%;
    background-repeat: no-repeat;
    }
    .currency input {
    border: 0;
    background: transparent;
    font-size: 30px;
    text-align: right;
    }
    .swap-rate-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    }
    .rate {
    color: var(--primary-color);
    font-size: 14px;
    padding: 0 10px;
}
select:focus,
input:focus,
button:focus {
    outline: 0;
}
@media (max-width: 600px) {
    .currency input {
        width: 200px;
    }
}
JavaScript代码
// 获取货币1对象
let currencyEl_one = document.getElementById("currency-one");
// 获取货币2对象
let currencyEl_two = document.getElementById("currency-two");
// 获取货币1对应的汇率对象
let amountEl_one = document.getElementById("amount-one");
// 获取货币2对应的汇率对象
let amountEl_two = document.getElementById("amount-two");
// 获取提示框对应的对象
let rateEl = document.getElementById("rate");
// 检查初始状态下 是否需要换算汇率
getData();
// 货币2发生变化时 触发的事件
currencyEl_two.onchange = getData;
// 货币1发生变化时 触发的事件
currencyEl_one.onchange = getData;
// 获取按钮 货币1和货币2是否都有值
let btn = document.getElementById("swap");
// 点击交换按钮时 触发的事件
btn.onclick = function() {
    // console.log("!!!");
    let currency_one = currencyEl_one.value;
    let currency_two = currencyEl_two.value;
    // 定义临时变量
    let temp = currency_one;
    // 交换货币1和货币2的value
    currencyEl_one.value = currency_two;
    currencyEl_two.value = temp;
    // 并且交换货币1和货币2对应的汇率
    currency_one = currency_two;
    currency_two = temp;
    fetch(`https://api.exchangerate-api.com/v4/latest/${currency_one}`)
        .then(res => res.json())
        .then(data => {
            const rate = data.rates[currency_two];
            rateEl.innerText = `1 ${currency_one} = ${rate} ${currency_two}`;
            amountEl_two.value = (amountEl_one.value * rate).toFixed(2);
        });
};
// 得到汇率
function getData() {
        let currency_one = currencyEl_one.value;
        let currency_two = currencyEl_two.value;
        fetch(`https://api.exchangerate-api.com/v4/latest/${currency_one}`)
            .then(res => res.json())
            .then(data => {
                const rate = data.rates[currency_two];
                rateEl.innerText = `1 ${currency_one} = ${rate} ${currency_two}`;
                amountEl_two.value = (amountEl_one.value * rate).toFixed(2);
            });
}
运行效果

作者:陈太浪
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须在文章页面给出原文连接,否则保留追究法律责任的权利。 
 
                    
                     
                    
                 
                    
                
 
                
            
         
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浙公网安备 33010602011771号