js点赞效果

<button id="likeButton">点赞</button>
<span id="likeCount">0</span>

document.getElementById('likeButton').addEventListener('click', function() {
    fetch('/like', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify({ contentId: '123' })
    })
    .then(response => response.json())
    .then(data => {
        document.getElementById('likeCount').textContent = data.likeCount;
    })
    .catch(error => console.error('Error:', error));
});

const express = require('express');
const app = express();
app.use(express.json());

let likeCount = 0;

app.post('/like', (req, res) => {
    const contentId = req.body.contentId;
    likeCount += 1;
    res.json({ likeCount });
});

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});