Eu tenho 2 tabelas, que é uma tabela de perguntas e uma tabela de respostas, a estrutura é assim:

E eu tenho uma matriz JSON que obtive de question_table e answer_table usando php como est

// to get the question
$pertanyaan = "select * from question_table”;
$resultPertanyaan = mysqli_query($con, $pertanyaan);

while($rowQuery= mysqli_fetch_array($resultPertanyaan)){
   $array_question[]= 
array('id'=>$rowQuery['id’],’question’=>$rowQuery['question']);
}

e o resultado é assim

array_question :
[
    {
        "id": "8",
        “question”: "Shop sign/billboard  "
    },
    {
        "id": "10",
        "question": "Pylon"
    },
    {
        "id": “11”,
        “question”: "Banner”
    },
    {
        "id": "12”,
        "question": “Sport”
    },
   {
        "id": “14”,
        “question”: “Matic "
    },
    {
        "id": "16”,
        "question": “Cub”
    }
]

Para obter a resposta

$jawaban = "select * from answer_table”;
$resultJawaban = mysqli_query($con, $jawaban);

while($rowQuery= mysqli_fetch_array($resultJawaban)){
    $array_answer[]=
array('id'=>$rowQuery['id'],'remark'=>$rowQuery['remark'],'item'=>$rowQuery['item']);
}

e o resultado assim

array_answer :
[
    {
        "id": "1b9fa84e-0f2f-11e9-b673-005056be36b2",
        “answer”: "3",
        “id_question”: "16"
    },
    {
        "id": "bc82c3fd-0f2e-11e9-b673-005056be36b2",
        "answer": "1",
        "id_question": "11"
    },
    {
        "id": "cc9363f1-0f2e-11e9-b673-005056be36b2",
        "answer": "3",
        "id_question": "12"
    },
    {
        "id": "f1dfa8b5-0f2e-11e9-b673-005056be36b2",
        "answer": "1",
        "id_question": "14"
    }
]

Eu quero combinar array_answer com array_question, que resulta desta forma:

array_result :
[
    {
        "id": "8",
        “question”: "Shop sign/billboard  ",
        “asnwer” : null
    },
    {
        "id": "10",
        "question": "Pylon”,
        “asnwer” : null
    },
    {
        "id": “11”,
        “question”: "Banner”,
        “asnwer” : “1”
    },
    {
        "id": "12”,
        "question": “Sport”,
        “answer” : “3”
    },
    {
        "id": “14”,
        “question”: “Matic “,
        “answer” : “1”
    },
    {
        "id": "16”,
        "question": “Cub”,
        “answer” : “3”
    }
]

Como obtenho array_result como eu esperava? Por favor me ajude, obrigad