How to write an example code for developing PHP interfaces?

Here is a simple example code demonstrating how to develop an API using PHP.

<?php

// 配置响应头，允许跨域访问
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");

// 接收请求参数
$param1 = $_GET['param1'];
$param2 = $_GET['param2'];

// 处理请求，这里只是简单的将两个参数进行相加
$result = $param1 + $param2;

// 构造响应数据
$response = array(
    "result" => $result
);

// 返回响应数据
echo json_encode($response);

?>

The code above utilizes the header function to set the response header, allowing cross-origin access. It then uses $_GET to retrieve request parameters, processes the parameters to construct response data, and uses json_encode to convert the response data to JSON format. Finally, it uses echo to output the response data.

This is just a simple example code, in actual development, more complex handling may be needed depending on specific requirements, such as database operations, calling other interfaces, etc.