如何在 JSON 响应中返回数组而不是对象？

Question

I've one working REST API developed using Slim PHP framework.

It's working absolutely fine.

The only issue is when there is no error present ie an array $errors is empty it comes as an array in JSON response but when the array $errors contains any error like $errors['user_name'] then it comes as an object in JSON response.

Actually I want to return the array when error is present. How should I do this? Can someone please help me in this regard?

Thanks in advance.

Answer 1

When your $errors is not empty, pass it through json_encode and echo it. It will give you JSON object in return, then convert JSON object into JavaScript array. (see the following code.)

var o = {"0":"1","1":"2","2":"3","3":"4"}; // your response object here 

var arr = Object.keys(o).map(function(k) { return o[k] });

console.log(arr);

Answer 2

Recently got a close issue with Symfony's JsonResponse::create()

Turns out arrays with index not starting at 0 will be encoded into objects, as well as arrays with "holes" , and probably any array with at least one non-int key .

In other word, arrays with anything else than consecutive numeric keys starting from index 0 seem to be encoded as object.

I guess this is designed to avoid sending big empty arrays when you map a handful of datas with big indices like [14334, 839493, 246193], and is probably documented somewhere.

Learning if this is a Symfony of json_encode behavior from comments would be welcomed addition :)


Note : Even if you return an array, it seems necessary to wrap it in an object for GET request to prevent some XSSI and JSON-JavaScript Hijacking .