Why does Ajax return an error even if the status is 200?

Question

PHP

answers[1] = {
    "answid": 12,
    "ans_val": 4325,
    "quest_id": 54,
    }
    answers[2] = {
    "answid": 13,
    "ans_val": 43151,
    "quest_id": 64,
    }
   
            $.ajax({
                url: "/Results.php",
                type: "POST",
                data: {answers: JSON.stringify(answers)},
                dataType: 'json',
                success: function (results) {
                    $.each(results, function (key, val) {
                        if (val.res == "good") {
                        alert("Success");
                        }else if(val.res =="bad"){
                        alert("Fail");
                        }
                    }
                 },
                error: function (err){
                  console.log(err);
            }
            });

if($this->SqlError==null){
        return [
            "data"=>[
                'res' => "good",
                'all_answers' => 3,
                'sub' => 3,
            ],
        ];
    }else{
        return [
            "error"=>$this->SqlError["error"],
        ];
    }

I am trying to get test results. I post Q&A but can't get the result in json format. When dataType: "json" ajax always returns an error, although the results are sent to the database, and when dataType: "text" ajax already accepts it as success BUT it is already as a string and + I receive this response with the data that I sent for processing and because of this some sort of conflict. Someone can help me with this? Thanks in advance

Answer 1

My problem was that I put extra echo / var_dump / print to check the data. Make sure you only have one echo ajax success