# Sending GET requests via AJAX in JavaScript

Let's now learn how to send data to a server in an AJAX request. The server will do something with this data and send back the result to us.

Our test server will process data sent to `/handler/`:

`button.addEventListener('click', function() { let promise = fetch('/handler/'); });`

First, let's send a GET request:

`button.addEventListener('click', function() { let promise = fetch('/handler/?num=3'); });`

Let's get the sent data on the server side:

`export default { '/handler/': function({get}) { console.log(get.num); // shows 3 } }`

Let's do something with this data and send it back:

`export default { '/handler/': function({get}) { return get.num ** 2; } }`

On the client side, we get the result and output it somewhere:

`button.addEventListener('click', function() { fetch('/handler/?num=3').then( response => { return response.text(); } ).then( text => { console.log(text); } ); });`

On the client side, a div and a button are given. On button click, send two numbers to a server. Let the server find the sum of the passed numbers. Write the result in the div.

Let an array be given on a server. Let the server wait a number passed as a parameter and return an array element corresponding to that number. On clicking the button, send some number to the server, and display the server's response in a paragraph.

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