Anonymous Function

Callback as an Arrow Function

If you prefer, you can also write the same callback function as an ES6 arrow function, which is a newer type of function in JavaScript:

setTimeout(() => { 
    console.log("This message is shown after 3 seconds");
}, 3000);

Anonymous Function

An anonymous function is a function without a name. An anonymous function is often not accessible after its initial creation. Here is an example of an anonymous function expression (the name is not used):

var myFunction = function() { statements }

It is also possible to provide a name inside the definition in order to create a named function expression:

var myFunction = function namedFunction(){ statements }