Node.js socket.send() Method
The socket.send() method is an inbuilt application programming interface of class Socket within dgram module which is used to send the message from one socket to another.
Syntax:
socket.send(msg[, offset, length][, port][, address][, callback])
Parameters: This method takes the following parameter:
- msg: Message to be sent.
- offset: Offset in the buffer where the message starts.
- length: Number of bytes in the message.
- port: Destination port.
- address: Destination hostname or IP address.
- callback: Called when the message has been sent.
Return Value: This method does not return any value.
Example 1: In this example, we will see the use of socket.send() Method
Filename: index.js
Javascript
// Node.js program to demonstrate the // server.send() 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 reference of the server // by using ref() method const size = server.ref(); // Display the result console.log(size.eventNames()); }); // Client sending message to server // by using send() method client.send( "Hello" , 0, 7, 1234, "localhost" ); |
Output:
[ 'message' ] UDP String: Hello
Example 2: In this example, we will see the use of a socket.send() Method
Filename: index.js
Javascript
// Node.js program to demonstrate the // server.send() 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, () => { // Getting the reference of server // by using ref() method const size = server.ref(); // display the result console.log(size.eventNames()); }); // Client sending message to server // by using send() method client.send( "Hello" , 0, 7, 1234, "localhost" , (err) => { if (err) throw err; console.log( "message sent" ); }); |
Output:
server listening 0.0.0.0:1234 [ 'message', 'listening' ] message sent 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_send_msg_offset_length_port_address_callback
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