Node.js socket.connect() Method

The socket.connect() method is an inbuilt application programming interface of class Socket within dgram module which is used to connect the particular server to a particular port and address.

Syntax:

const socket.connect(port[, address][, callback]) 

Parameters: This method accepts the following parameters:

• port: This parameter holds the port number.
• address: This parameter holds the server address information.
• callback: This parameter holds the callback function for further operation.

Return Value: This method does not return any value.

Example 1: In this example, we will see the use of socket.connect() method

Filename: index.js

Javascript

// Node.js program to demonstrate the
// server.connect() method

// Importing dgram module
const dgram = require('dgram');

// Creating and initializing client
// and server socket
let client = dgram.createSocket("udp4");
let server = dgram.createSocket("udp4");

// Catching the message event
server.on("message", function (msg) {

    // Displaying the client message
    process.stdout.write("UDP String: " + msg + "\n");

    // Exiting process
    process.exit();
})
    // Binding server with port
    .bind(1234, () => {

        // Getting the address information
        // for the server by using
        // address method
        const address = server.address()

        // Display the result
        console.log(address);

    });

// Connecting the server with particular local host
// and address by using connect() method
server.connect(1234, "localhost", () => {
    console.log("connected")
})

// Client sending message to server
client.send("Hello", 0, 7, 1234, "localhost");

Output:

{ address: '0.0.0.0', family: 'IPv4', port: 1234 }
connected
UDP String: Hello

Example 2: In this example, we will see the use of socket.connect() method

Filename: index.js

Javascript

// Node.js program to demonstrate the
// server.connect() method

// Importing dgram module
const dgram = require('dgram');

// Creating and initializing client
// and server socket
let client = dgram.createSocket("udp4");
let server = dgram.createSocket("udp4");

// Catching the message event
server.on("message", function (msg) {

    // Displaying the client message
    process.stdout.write("UDP String: " + msg + "\n");

    // Exiting process
    process.exit();

});

// Catching the listening event
server.on('listening', () => {

    // Getting address information for the server
    const address = server.address();

    // Display the result
    console.log(`server listening
        ${address.address}:${address.port}`);

});


// Binding server with port address
// by using bind() method
server.bind(1234, () => {

    // Adding a multicast address for others to join
    server.addMembership('224.0.0.114');

});


// Connecting the server with particular local host
// and address by using connect() method
server.connect(1234, "localhost", () => {
    console.log("connected")
})

// Client sending message to server
client.send("Hello", 0, 7, 1234, "localhost");

Output:

server listening 0.0.0.0:1234
connected
UDP String: Hello

Run the index.js file using the following command:

node index.js

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/dgram.html#dgram_socket_connect_port_address_callback