##    
### Overview
In jQuery, the **`ajaxStart()`** method is used to specify a function that runs when an AJAX request starts.

### Syntax
```
$(document).ajaxStart(function());
```

### Parameters
This method accepts only one parameter that is a function that gets invoked when the request starts.

### Example

<html>
 <head>
   <title>jQuery | ajaxStart() 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(){
  // execute following function on click of button
  $("#btn").click(function(){
    // setting up an AJAX request
    $.ajax({
      url: 'https://reqres.in/api/products',
      method: "GET",
      processData: false,
      contentType: false,
      dataType: 'json',
      success: function(res) {
        // if request succeeds, append data to content div
        $('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`);
        });
      }
    });
  });

  // when the request starts, execute ajaxStart method
  $(document).ajaxStart(() => {
    console.log("ajaxStart method invoked. Request Started");
  })
})

button {
    background-color: #00008B;
    color: #ffffff;
    padding: 3px 9px;
    border: none;
    border-radius: 4px;
    height: 40px;
}

codemirror

console

### Explanation
We click the "Get Product Data" button and make an AJAX request [here](https://reqres.in/api/products) to get product details. We do this between **line 3 and line 19** in the "JavaScript" tab. 

When the AJAX request starts, the `ajaxStart()` method will be invoked.

What is ajaxStart() method in jQuery?

Overview

Syntax

Parameters

Example

Explanation