PHP printf在构建API响应中的应用

printf 是一个用于格式化字符串的 PHP 语言函数

1. 输出 JSON 数据：

<?php
$data = array(
    "name" => "John Doe",
    "age" => 30,
    "city" => "New York"
);

header('Content-Type: application/json');
echo printf(json_encode($data, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
?>

2. 输出 XML 数据：

<?php
$data = array(
    "user" => array(
        "id" => 1,
        "name" => "John Doe",
        "email" => "john.doe@example.com"
    )
);

header('Content-Type: application/xml');
echo printf(xml_encode($data, XML_PRETTY_PRINT | XML_USE_CDATA));
?>

3. 输出 CSV 数据：

<?php
$data = array(
    array("Name", "Age", "City"),
    array("John Doe", 30, "New York"),
    array("Jane Smith", 28, "Los Angeles")
);

header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename="data.csv"');

$fp = fopen('php://output', 'w');
foreach ($data as $row) {
    fputcsv($fp, $row);
}
fclose($fp);
?>

4. 输出自定义格式的数据：

<?php
$data = array(
    "name" => "John Doe",
    "age" => 30,
    "city" => "New York",
    "is_student" => false,
    "courses" => array("PHP", "MySQL", "JavaScript")
);

header('Content-Type: text/plain');
echo printf("%s is %d years old and lives in %s. %s is a student. He is studying the following courses: %s.\n",
    $data["name"],
    $data["age"],
    $data["city"],
    $data["is_student"] ? "Yes" : "No",
    implode(", ", $data["courses"])
);
?>

在构建 API 响应时，使用 printf 可以帮助你快速生成格式化的字符串，从而提高开发效率。同时，通过设置正确的 Content-Type 头，你可以确保客户端能够正确解析响应数据。