原生JS实现汇率转换功能代码实例

(编辑：jimmy 日期: 2024/11/26 浏览：3 次 )
代码如下
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" rel="external nofollow" />
</head>
<body>
<img src="/UploadFiles/2021-04-02/money.png">

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

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