php两个json怎么合并

PHP中合并两个JSON数据的实用方法

在PHP开发中,我们经常需要处理JSON数据，有时会遇到需要合并两个JSON对象的情况，本文将详细介绍几种在PHP中合并两个JSON数据的方法，帮助开发者高效解决这一问题。

解码为数组后合并再编码

这是最直接的方法,先将JSON字符串解码为PHP数组，使用PHP数组合并函数处理后再编码回JSON格式。

<?php
$json1 = '{"name":"John","age":30,"city":"New York"}';
$json2 = '{"name":"Alice","gender":"female","city":"London"}';
// 将JSON解码为PHP数组
$array1 = json_decode($json1, true);
$array2 = json_decode($json2, true);
// 合并数组（array_merge会覆盖重复的键）
$mergedArray = array_merge($array1, $array2);
// 将合并后的数组编码回JSON
$mergedJson = json_encode($mergedArray);
echo $mergedJson;
// 输出: {"name":"Alice","age":30,"city":"London","gender":"female"}
?>

注意：array_merge()会覆盖重复的键，后面的值会覆盖前面的值，如果需要保留所有值，可以考虑使用运算符：

$mergedArray = $array1 + $array2;

使用递归合并处理嵌套数组

当JSON数据包含嵌套结构时,简单的array_merge()可能不够用，这时可以使用递归合并函数：

<?php
function array_merge_recursive_distinct(array $array1, array $array2) {
    $merged = $array1;
    foreach ($array2 as $key => $value) {
        if (is_array($value) && isset($merged[$key]) && is_array($merged[$key])) {
            $merged[$key] = array_merge_recursive_distinct($merged[$key], $value);
        } else {
            $merged[$key] = $value;
        }
    }
    return $merged;
}
$json1 = '{"person":{"name":"John","age":30},"hobbies":["reading","swimming"]}';
$json2 = '{"person":{"name":"Alice","gender":"female"},"hobbies":["coding"],"city":"London"}';
$array1 = json_decode($json1, true);
$array2 = json_decode($json2, true);
$mergedArray = array_merge_recursive_distinct($array1, $array2);
$mergedJson = json_encode($mergedArray);
echo $mergedJson;
// 输出: {"person":{"name":"Alice","age":30,"gender":"female"},"hobbies":["reading","swimming","coding"],"city":"London"}
?>

使用JSON对象合并（PHP 7.4+）

如果使用的是PHP 7.4或更高版本，可以利用对象合并的语法：

<?php
$json1 = '{"name":"John","age":30}';
$json2 = '{"name":"Alice","gender":"female"}';
$obj1 = json_decode($json1);
$obj2 = json_decode($json2);
// 合并对象（后面的属性会覆盖前面的）
$mergedObj = (object) array_merge((array) $obj1, (array) $obj2);
$mergedJson = json_encode($mergedObj);
echo $mergedJson;
// 输出: {"name":"Alice","age":30,"gender":"female"}
?>

使用第三方库

对于更复杂的合并需求,可以考虑使用第三方库如Symfony的ArrayUtils或Zend的ArrayUtils：

<?php
// 使用Symfony的ArrayUtils
require_once 'vendor/autoload.php';
use Symfony\Component\PropertyAccess\PropertyAccess;
$json1 = '{"user":{"name":"John","age":30},"settings":{"theme":"dark"}}';
$json2 = '{"user":{"name":"Alice","gender":"female"},"settings":{"theme":"light","notifications":true}}';
$array1 = json_decode($json1, true);
$array2 = json_decode($json2, true);
$accessor = PropertyAccess::createPropertyAccessor();
$mergedArray = $accessor->setValue($array1, '', $array2);
$mergedJson = json_encode($mergedArray);
echo $mergedJson;
// 输出: {"user":{"name":"Alice","age":30,"gender":"female"},"settings":{"theme":"light","notifications":true}}
?>