How to accept front-end data in php and convert it into json

In the development mode where the front and back ends are separated, the data transmission of the front and back ends uses the RESTful interface. The front end obtains data through AJAX requests, while the back end uses PHP scripts to process the requests and encapsulate the data into JSON format and return it to the front end.

As a popular server-side scripting language, PHP can easily accept front-end requests and convert the data required by the request into JSON format.

1. Why use JSON?

JSON is a lightweight data exchange format that is widely used in data transmission. It is characterized by simple syntax, good readability, and easy parsing and generation.

Using JSON has the following advantages:

1. Save bandwidth: The amount of data transmitted in JSON format is small and does not occupy too much server bandwidth.

2. Easy to parse: JSON format is a simple data exchange format that is easy to parse and generate. The required data can be quickly parsed.

3. Cross-language support: Since JSON is widely used in data transmission, various programming languages ​​have tool libraries that support JSON parsing and generation.

4. Easy to debug: Data transmitted in JSON format can be viewed and debugged through browser development tools, making it easy to troubleshoot problems and optimize code.

2. Use PHP to process front-end requests and return JSON data

In PHP, we can process front-end requests and return JSON data through the following steps:

1 .Receive front-end request data

In PHP, we can receive data passed by the front-end through global variables such as $_GET, $_POST, $_REQUEST. For example, receive the name and age passed by the front end:

$name = $_POST['name'];
$age = $_POST['age'];

2. Processing Request and query the database

According to the business logic of the front-end request, we process the request and query the database through PHP code. For example, query user information based on the ID passed by the front end:

$id = $_GET['id'];
$sql = "SELECT * FROM user WHERE id =".$id;
$result = mysqli_query($conn,$sql);

3. Convert the result to JSON format

In PHP, we can convert arrays or objects into JSON through the json_encode() function Format. For example, convert the query results into JSON format:

$data = array();
while ($row = mysqli_fetch_assoc($result)){
array_push($data,$row);
}
echo json_encode($data);

4. Set the response header

In order for the front end to correctly parse the returned JSON data, we need to set the response header Content-type for application/json. For example:

header('Content-Type: application/json');

Finally, the execution result of the PHP script will be encapsulated into JSON format and returned to the front end.

Summary

In the development mode where the front and back ends are separated, the data transmission of the front and back ends uses the RESTful interface. The front end obtains data through AJAX requests, while the back end uses PHP scripts to process the requests and encapsulate the data into JSON format and return it to the front end.

In PHP, we can receive the data passed by the front end through global variables such as $_GET, $_POST, $_REQUEST, etc., process the request and query the database through PHP code, and then use the json_encode() function to convert the query results Convert it into JSON format and return it to the front end.

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