In jQuery, the **`ajaxSend()` method** is used to specify a function that runs when an AJAX request is about to be sent.

#   
#  Syntax
```
$(document).ajaxSend(function(event, xhr, options));
```

#    
## Parameters
This method accepts a mandatory function that accepts the following parameters:
* **`event`**: This is the event object.
* **`xhr`**: This is the instance of the XMLHttpRequest object.
* **`options`**: These are the options that are used in AJAX requests.

## 
## Example

The following tab will show us the `ajaxSend()` function in action:

> **Note**: Press the "Get Product Data" button to see the `ajaxSend()` function in action.

<html>
 <head>
   <title>jQuery | ajaxSend() example</title>
   <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
 </head>
 <body>
   <button id="btn">Get Product Data</button>
   <div id="content"/>
 </body>
</html>

$(document).ready(function(){
  $("#btn").click(function(){
    $.ajax({
      url: 'https://reqres.in/api/products',
      method: "GET",
      processData: false,
      contentType: false,
      dataType: 'json',
      success: function(res) {
        $('p').add(`<span>ID</span> <span>Name</span><br>`).appendTo(`#content`);
        $.each(res.data, function(index, obj) {
          $('p').add(`<span>${obj.id}</span> <span>${obj.name}</span><br>`).appendTo(`#content`);
        });
      }
    });
  })
  $(document).ajaxSend(() => {
    console.log("Ajax request is about to send");
  })
})

button {
    background-color: #00008B;
    color: #ffffff;
    padding: 3px 9px;
    border: none;
    border-radius: 4px;
    height: 50px;
    width: 150px;
}

codemirror

console

#  
## Code explanation

We made a GET request on https://reqres.in/api/products to fetch some product details.

Just before the AJAX request is about to be sent, the `ajaxSend()` method will be invoked.

What is the ajaxSend() method in jQuery?

Specifies a function to run before an AJAX request is sent using the event, xhr, and options parameters.