Callback Function - Javascript [verified]

The "outer" function that receives and executes the callback. Basic Syntax Example javascript

function greetUser(name, callback) { console.log('Hello, ' + name); callback(); // Executing the passed function } function sayGoodbye() { console.log('Goodbye!'); } // sayGoodbye is passed as the callback greetUser('Alice', sayGoodbye); Use code with caution.

Understanding when a callback executes is critical for managing a program's side effects. callback function javascript

A in JavaScript is a function passed as an argument into another function, which is then invoked (or "called back") inside the outer function to complete a routine or action. Because functions in JavaScript are first-class objects , they can be treated like any other variable, allowing them to be passed around and executed at a specific later time.

In this example, greetUser is the higher-order function, and sayGoodbye is the callback. The output will be: Hello, Alice Goodbye! . The "outer" function that receives and executes the callback

These are executed later, after an asynchronous operation—such as a network request or a timer—has completed. This allows the rest of the code to keep running without being blocked. Callback function - Glossary - MDN Web Docs - Mozilla

These are executed immediately during the execution of the outer function. The program waits for the callback to finish before moving to the next line. A in JavaScript is a function passed as

Functional programming methods like Array.prototype.map(), filter() , and forEach() . Asynchronous Callbacks