node.js: how to use setInterval and clearInterval?

You can use "this" in the following example:

const dgram = require('dgram');
const message = Buffer.from('from raspberry pi 3');
const client = dgram.createSocket('udp4');
var count = 0;

function intervalFunc() {
  count++;
  client.send(message, 3001, 'localhost', (err) => {
    //client.close();
  });
  if (count == '5') {
    clearInterval(this);
  }
}
setInterval(intervalFunc, 1500);

If you want a JavaScript like interval ID after creating a setInterval timer, you can do the following,

function callbackFunc() {
  console.log("I'm just an example callback function");
}

const timeoutObj = setInterval(callbackFunc, 1000);
const intervalId = timeoutObj[Symbol.toPrimitive](); //intervalId is an interger

// Later you can clear the timer by calling clearInterval with the intervalId like,
clearInterval(intervalId);

Note: This only works when your node version is >= v12.19.0.

Using setInterval()

What if you need to repeat the execution of your code block at specified intervals? For this, Node has methods called setInterval() and clearInterval(). The setInterval() function is very much like setTimeout(), using the same parameters such as the callback function, delay, and any optional arguments for passing to the callback function.

A simple example of setInterval() appears below:

var interval = setInterval(function(str1, str2) {
  console.log(str1 + " " + str2);
}, 1000, "Hello.", "How are you?");

clearInterval(interval);

This is another way when you want to keep only one interval running every minute

function intervalFunc() {
    console.log("Hello!!!!");
     }
    setInterval(intervalFunc,1500);

In the above example, intervalFunc() will execute about every 1500 milliseconds, or 1.5 seconds, until it is stopped . Hope this helps.

This just caught me. Exactly the same scenario, clearInterval simply wasn't working.

Looking in the console, the result of setInterval was an object, not a number. I was quite confused.

The solution was to remove this import statement, which had snuck in:

import { setInterval } from 'timers';