如何将JavaScript数组发送到php文件并将其与数据库进行比较？

Question

I have made an online examination portal where different question are being loaded on the page from database using ajax and php when a button is clicked.The array is collecting the radio option value selected by the user i cant send the array to the php file ?Please Help.

The HTML code:-

Question Palette:

            <div class="container">
            <div>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(1)" style="margin-right:16px">1</button>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(2)" style="margin-right:16px">2</button>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(3)" style="margin-right:16px">3</button>
            </div><br>
            <div>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(4)" style="margin-right:16px">4</button>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(5)" style="margin-right:16px">5</button>
                <button type="button" class="btn btn-info custom" onclick="updateQuestion(6)" style="margin-right:16px">6</button>
            </div><br>
            <div>
                <button type="button" class="btn btn-info custom"   onclick="updateQuestion(7)" style="margin-right:16px">7</button>
                <button type="button" class="btn btn-info custom"   onclick="updateQuestion(8)" style="margin-right:16px">8</button>
                <button type="button" class="btn btn-info custom"   onclick="updateQuestion(9)" style="margin-right:16px">9</button>
            </div><br>


<button type="button" class="btn btn-info btn-md" id="mark" onclick="loadNextQues(1)">Mark for Review & Next</button>
            <button type="button" class="btn btn-info btn-md">Clear Response</button>
            <button type="submit" class="btn btn-info btn-md" id="save" style="position:absolute;right:20px;bottom:35px" onclick="loadNextQues(0)">Save and Next</button>
<form action="check.php">
            <button type='submit' class="btn btn-info btn-md" id="water" style="visibility:hidden;position:absolute;right:20px;bottom:35px" onclick="Checkanswers()">submit</button>
            </div></div><br>

Here is the javascript code:-

var arr=new Array();
function loadNextQues(flag){
        quesno++;
var Selected = document.querySelectorAll('[name="op"]:checked');
        if (Selected != null) {
        Selected.forEach(function(radio) {
        arr.push(radio.value);
        });
        }
        else{

            arr.push(0);
        }

        console.log(arr);
if(flag==1){
            //add css to the button for  mark for review
        }
        else{
            //add css for the button as answered
        }
        url="http://localhost/assignments/load-questions.php?qno="+quesno;
        $.get(url,function(data,status){
            response=JSON.parse(data);
            console.log(response);
            var quest="<p>"+response.qno+" "+response.question+"</p>";
            quest+="<form>";
            quest+="<input type=\"radio\" name=\"op\" value='"+response.opA +"'>A."+response.opA+"<br>";
            quest+="<input type=\"radio\" name=\"op\" value='"+response.opB +"'>B."+response.opB+"<br>";
            quest+="<input type=\"radio\" name=\"op\" value='"+response.opC +"'>C."+response.opC+"<br>";
            quest+="<input type=\"radio\" name=\"op\" value='"+response.opD +"'>D."+response.opD+"<br>";
            quest+="</form>";
            document.getElementById("questBox").innerHTML=quest;

    });

}

function Checkanswers(){
        var Selected = document.querySelectorAll('[name="op"]:checked');
        if (Selected != null) {
        Selected.forEach(function(radio) {
        arr.push(radio.value);
        });

        }
        else{
            arr.push(0);
        }
        alert(JSON.stringify(arr));
        $.get({
            url:"check.php",
            data: {myarray : JSON.stringify(arr)},
            success: function(data)
            {
                alert(data);
            }
        });

    }

Here is the check.php code:-

<?php

session_start();
require 'includes/dbh.inc.php';

$array = array();

$arr =$_GET["myarray"];

$arr1=substr($arr,1,strlen($arr)-1);

$array=explode(',',$arr1);

$result = 0;
$i= 1;
$sql = " SELECT * FROM questionpaper ";
$query = mysqli_query($conn,$sql);
while($rows = mysqli_fetch_array($query)){

    $checked = ($rows['ans'] ==  (int)$array[$i]) ;

    if($checked){

        $result++;

    }
    $i++;

}

echo "<br> Your total score is".$result;



?>

error:-

Notice: Undefined index: myarray in D:\XAMPP\htdocs\assignments\check.php on line 8
Notice: Undefined offset: 1 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 2 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 3 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 4 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 5 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 6 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 7 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 8 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 9 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 10 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 11 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 12 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 13 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 14 in D:\XAMPP\htdocs\assignments\check.php on line 20
Notice: Undefined offset: 15 in D:\XAMPP\htdocs\assignments\check.php on line 20

Answer 1

It is obvious in your code that the "myarray" variable You are trying to get with PHP using $arr =$_GET["myarray"] was not defined in your JavaScript, Neither was it sent to the server, so PHP has nothing to retrieve.

In your code, you seem to be storing the array with var arr. You should change

url="http://localhost/assignments/load-questions.php?qno="+quesno;

To

url="http://localhost/assignments/load-questions.php?qno="+quesno+"&myarray="+arr;