in JavaScript Technology

How to Use Data of a JSON in JavaScript with Ajax

When using the data of JSON file in HTML document some errors that could occur. One of them that usually happens is as follows:

  • Access to XMLHttpRequest has been blocked by CORS policy

Here is an example of a test.

Step 1. Created JSON file New.json

[
    { "firstname":"Thomas", "lastname":"Anderson" },
    { "firstname":"Agent", "lastname":"Smith" },
    { "firstname":"Agent", "lastname":"Brown" }
]

Step 2. And to get the data from JSON file try the following code:

<script type="application/javascript">
            $(document).ready(function() {
                $("div").click(function () {
                    $.ajax({
                        type: 'GET',
                        url: './New.json',
                        dataType: 'json',
                        success: function(data){
                            window.alert(data);
                        },
                    });
                });
            });
    </script>

As a result got the following error: Access to XMLHttpRequest has been blocked by CORS policy

https://i.stack.imgur.com/iC20z.png
Access to XMLHttpRequest has been blocked by CORS policy error screenshot

One of the solutions could be instead of surrounding the list of elements with {} which produces an invalid object, use [] to make a valid array.

If that doesn’t help read the following guide Cross-domain Ajax with Cross-Origin Resource Sharing

Click here to view original web page at stackoverflow.com