Ajax
它的全称是:Asynchronous JavaScript And XML,翻译过来就是“异步的 Javascript 和 XML”。
const SERVER_URL = "/server";
let xhr = new XMLHttpRequest();
// 创建 Http 请求
xhr.open("GET", SERVER_URL, true);
// 设置状态监听函数
xhr.onreadystatechange = function() {
if (xhr.readyState !== 4) return;
// 当请求成功时
if (xhr.status === 200 || xhr.status === 304) {
console.log(xhr.responseText);
} else {
console.error(xhr.statusText);
}
};
// 发送 Http 请求
xhr.send();
//使用Promise封装AJAX请求
const getJSON = function (url) {
return new Promise((resolve, reject) => {
const xhr = new XMLHttpRequest();
xhr.open("GET", url, false);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function () {
if (xhr.readyState !== 4) return;
if (xhr.status === 200 || xhr.status === 304) {
resolve(xhr.responseText);
} else {
reject(new Error(xhr.responseText));
}
};
xhr.send();
});
};
Fetch
<body>
<script>
function ajaxFetch(url) {
fetch(url).then(res => res.json()).then(data => {
console.info(data)
})
}
ajaxFetch('https://smallpig.site/api/category/getCategory')
</script>
</body>
Axios