How to Transmit JSON Data to PHP Using Ajax

In order to convey data to a PHP script in JSON format, it is crucial to be able to send the data effectively using AJAX.

Sending JSON Data

The provided code illustrates an attempt to send JSON data using AJAX:

$.ajax({
  type: "POST",
  dataType: "json",
  url: "add_cart.php",
  data: {myData: dataString},
  success: function(data){
    alert('Items added');
  },
  error: function(e){
    console.log(e.message);
  }
});

Receiving JSON Data in PHP

On the PHP side, access the data as follows:

if(isset($_POST['myData'])){
  $obj = json_decode($_POST['myData']);
  // Perform desired PHP operations
}

Troubleshooting

If you encounter an empty array (array(0) {}) when printing $_POST in the PHP script, it is most likely due to an error in the AJAX request.

Remove the line contentType: "application/json; charset=utf-8" from the AJAX request. This is not necessary as the data is already being sent as a string.

Simplified Approach

Alternatively, you can simplify the process by omitting the JSON encoding/decoding:

data: {myData: postData},

$obj = $_POST['myData'];

This approach sends the data as a plain object, eliminating the need for additional transformations.