If you write JavaScript, you have probably used higher-order functions and not even noticed. If you have ever replaced a for loop with an array method, you’ve used higher-order functions.

Let’s begin by looking at an HTML form and some vanilla JavaScript to go with it, as shown in Listing 1. You can also see this example running in a live fiddle. Listing 1. A simple HTML form ...

Simply create a JavaScript function that contains the statement and call it whenever you need a text box. However, you can also set the text box's value and ID attributes as follows: ...

In this example that server-side resource is named upload.php When notified that the JavaScript file upload was successful, send an Ajax based alert to the client. All the HTML and JavaScript logic ...