js+怎么提交数据到后台

function sendData() {
    var xhr = new XMLHttpRequest();
    var url = "your-backend-endpoint";
    var data = JSON.stringify({ key: "value" });

    xhr.open("POST", url, true);
    xhr.setRequestHeader("Content-Type", "application/json");
    xhr.onreadystatechange = function () {
        if (xhr.readyState === 4 && xhr.status === 200) {
            console.log(xhr.responseText);
        }
    };
    xhr.send(data);
}

function sendData() {
    var url = "your-backend-endpoint";
    var data = { key: "value" };

    fetch(url, {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(data)
    })
    .then(response => response.json())
    .then(data => console.log(data))
    .catch((error) => console.error('Error:', error));
}

npm install axios

import axios from 'axios';

function sendData() {
    var url = "your-backend-endpoint";
    var data = { key: "value" };

    axios.post(url, data)
        .then(response => console.log(response.data))
        .catch(error => console.error('Error:', error));
}