Schedule task with setTimeout and setInterval using javascript

The setTimeout and setInterval functions in JavaScript can schedule the task. We main difference between setTimeout and setInterval functions is as below:

• setTimeout: execute the function after waiting for a certain amount of time. It will execute the function once.
• setInterval: It executes the function repeatedly after waiting for a certain amount of time.

lets we have a function that alerts message on the browser and can be defined in javascript as below:

function alertMsg(){
  alert("I am an alert box!!");
}

We can execute the alert() function using SetTimeout and setInterval after waiting for some time.

setTimeout

In Javascript, we can write the setTimeout function as below

setTimeout(alertMsg, 1000); // Will alert once, after a second.

We don’t need to clear setTimeout as it only executes the function once.

setInterval

In JavaScript, we can write the setInterval function as below:

var intervalID = setInterval(alertMsg, 1000); // Will alert every second.

If we want to clear the setInterval to execute the function repeatedly, we can write the below command in javascript:

clearInterval(intervalID); // Will clear the timer.

If we want to execute the function once using setInterval() function, we can rewrite our function as below:

function alertMsg(){
  alert("I am an alert box!!");
  clearInterval(intervalID);
}