这里是json

{"msg":"OK","server_time":"2021-11-19 16:41:22","status":200,"result":{"total_pages":1,"files":[{"download_url":"DOWNLOADLINKHERE1","single_img":"IMAGEURLHERE1","file_code":"CODEHERE1","title":"TITLEHERE1"},{"download_url":"DOWNLOADLINKHERE2","single_img":"IMAGEURLHERE2","file_code":"CODEHERE2","title":"TITLEHERE2"}],"results_total":"2","results":2}} 

这是我的代码：

$json = json_decode($data); foreach($json["result"] as $result){ foreach($result["files"] as $file){ echo $file["file_code"];
    } } 

我想从"file_code"中提取所有值。我收到一个错误警告：为foreach（）提供的参数无效

将$json['result']视为对象，因此下一行测试total_pages["files"]，它不存在。

将两个foreach放在一起可以解决问题：

$data='{"msg":"OK","server_time":"2021-11-19 16:41:22","status":200,"result":{"total_pages":1,"files":[{"download_url":"DOWNLOADLINKHERE1","single_img":"IMAGEURLHERE1","file_code":"CODEHERE1","title":"TITLEHERE1"},{"download_url":"DOWNLOADLINKHERE2","single_img":"IMAGEURLHERE2","file_code":"CODEHERE2","title":"TITLEHERE2"}],"results_total":"2","results":2}}';

$json = json_decode($data, true);
foreach($json["result"]["files"] as $file) print $file["file_code"]; 

或者，将JSONresult放入数组，并使用对象属性访问器而不是关联数组绑定。

$data='{"msg":"OK","server_time":"2021-11-19 16:41:22","status":200,"result":[{"total_pages":1,"files":[{"download_url":"DOWNLOADLINKHERE1","single_img":"IMAGEURLHERE1","file_code":"CODEHERE1","title":"TITLEHERE1"},{"download_url":"DOWNLOADLINKHERE2","single_img":"IMAGEURLHERE2","file_code":"CODEHERE2","title":"TITLEHERE2"}],"results_total":"2","results":2}]}';
$json = json_decode($data);
foreach($json->result as $result){
    foreach($result->files as $file){
        echo $file->file_code;
    }
}