Making JSONP Requests from JavaScript Without External Libraries

For cross-domain JSONP requests in JavaScript, external libraries like jQuery aren't always necessary. Here's a guide on achieving this using pure JavaScript:

Step 1: Create a Callback Function

Start by defining a callback function to receive and process the JSONP response. In the example provided, the foo function performs this task:

function foo(data) {
  // Do something with the JSON response here
}

Step 2: Dynamically Create a Script Element

Next, create a

var script = document.createElement('script');
script.src = '//example.com/path/to/jsonp?callback=foo';

Step 3: Append the Script Element to the DOM

Once the

document.getElementsByTagName('head')[0].appendChild(script);

For modern browsers, you can simplify this line to:

document.head.appendChild(script);

Example

Bringing these steps together, here's a complete example of making a JSONP request in JavaScript without an external library:

function foo(data) {
  // Do stuff with JSON
}

var script = document.createElement('script');
script.src = '//example.com/path/to/jsonp?callback=foo'

document.head.appendChild(script);