建立 UDP 伺服器

const dgram = require('dgram');

const server = dgram.createSocket('udp4');
// 建立 message 事件的接收器
server.on('message', (msg, rinfo) => {
    console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`);
    // 伺服器發訊息
    server.send("message '" + msg + "' received!",
    rinfo.port, rinfo.address);
});

// 設定偵聽事件的響應
server.on('listening', () => {
    const address = server.address();
    console.log(`server listening ${address.address}:${address.port}`);
});

// 繫結到埠上
server.bind(4333);

建立 UDP 客戶端

const dgram = require('dgram');

const client = dgram.createSocket('udp4');

const message = Buffer.from('Udp 客戶端請求');

// 傳送訊息
client.send(message, 4333, 'localhost', (err) => {
  client.close();
});
// 客戶端收訊息
client.on("message", (msg, rinfo) => {
	console.log(`client got: ${msg} from ${rinfo.address}:${rinfo.port}`);
	console.log("message from server, received");
	console.log("message is" + msg);
	client.close();
});