Difference Between setTimeout & setInterval in JavaScript

JavaScript has both setTimeout and setInterval functions that are used for executing code after a certain delay. However, they differ in how they handle the timing of execution. Understanding their differences is crucial for effectively managing asynchronous operations in our code which is explained below:

Using setTimeout

setTimeout is a function in JavaScript used to execute a piece of code or a function after a specified delay. It allows you to execute a function only once after a certain amount of time has passed.

Syntax:

setTimeout(function, delay);

Example: Printing the output "Hello World!" after 2 seconds of code execution.

function greet() {
    console.log("Hello, world!");
}

// Executes greet function after 2 seconds
setTimeout(greet, 2000); 

Output:

Using setInterval

setInterval is another function in JavaScript used to execute a piece of code or a function repeatedly at a fixed interval. It allows you to execute a function repeatedly with a specified time delay between each execution.

Syntax:

setInterval(function, delay);

Example: To demonstrate printing the time at interval of 1 seconds.

function displayTime() {
    console.log(new Date().toLocaleTimeString());
}


// Executes displayTime function every second
setInterval(displayTime, 1000); 

Output:

Difference between setTimeout and setInterval