// 创建 XMLHttpRequest 对象
var xhr = new XMLHttpRequest();

// 配置请求
xhr.open('POST', 'process.php', true);
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');

// 设置回调函数
xhr.onreadystatechange = function() {
    if (xhr.readyState == 4 && xhr.status == 200) {
        console.log(xhr.responseText);
        // 处理服务器返回的数据
    }
};

// 发送数据
var data = 'name=' + encodeURIComponent('John') + '&age=' + encodeURIComponent(30);
xhr.send(data);

$.ajax({
    type: "POST",
    url: "process.php",
    data: {
        name: "John",
        age: 30
    },
    success: function(response) {
        console.log(response);
        // 处理服务器返回的数据
    },
    error: function(xhr, status, error) {
        console.error(error);
    }
});

<?php
// 检查是否是 POST 请求
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // 获取 POST 数据
    $name = isset($_POST['name']) ? $_POST['name'] : '';
    $age = isset($_POST['age']) ? $_POST['age'] : '';
    
    // 数据验证
    if (empty($name) || empty($age)) {
        http_response_code(400);
        echo json_encode(['error' => 'Name and age are required']);
        exit;
    }
    
    // 处理数据
    $response = [
        'status' => 'success',
        'message' => 'Data received',
        'data' => [
            'name' => htmlspecialchars($name),
            'age' => intval($age)
        ]
    ];
    
    // 返回 JSON 响应
    header('Content-Type: application/json');
    echo json_encode($response);
} else {
    http_response_code(405);
    echo json_encode(['error' => 'Method not allowed']);
}
?>

fetch('process.php', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
    },
    body: JSON.stringify({name: 'John', age: 30})
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error(error));

axios.post('process.php', {
    name: 'John',
    age: 30
})
.then(response => console.log(response.data))
.catch(error => console.error(error));