How do i send a 2d array with ajax? - php

Question

I am currently trying to send a 2d array that i receive from a database (sql, phpmyadmin) with ajax.
My ajax function looks like this: (it is generated in php)
$.ajax({
type: \"POST\",
url: \"resultQuizGet.php\",
data: \"getAnswer=\"+question+\"\", //question is just a int variable
success: function(msg) {
alert(\"Data Saved: \" + msg);
}
});
my resultQuizGet.php file then look like
$sql = "SELECT `quiz`.question,`quiz`.rightAnswer
FROM `quiz`
WHERE `quiz`.quizID=:qID";
$stmt = $dbh->prepare($sql);
$stmt->bindParam(":qID", $_POST['quiz']);
$stmt->execute();
$resultsQuiz = $stmt->fetchAll();
echo ...
What do i have to do now to receive a 2d array instead of just a normal string.
What i would like to the msg variable to be is a 2d array that is equal to $resultsQuiz

Answer 1

Modify your php as follows, to output the data as a json formatted string:
$sql = "SELECT `quiz`.question,`quiz`.rightAnswer
FROM `quiz`
WHERE `quiz`.quizID=:qID";
$stmt = $dbh->prepare($sql);
$stmt->bindParam(":qID", $_POST['quiz']);
$stmt->execute();
$resultsQuiz = $stmt->fetchAll();
echo json_encode($resultsQuiz);
Then, modify your jQuery as follow to parse that structured string back into an array / object:
$.ajax({
type: "POST",
url: "resultQuizGet.php",
data: "getAnswer="+question, //question is just a int variable
success: function(msg) {
// Note: if it's not json, this can cause a problem
var data = $.parseJSON(msg);
// output to your console so you can see the structure
console.log(data);
// Utilize the data somehow
$.each(data, function(key, arr) {
// Arr should contain an object / array representing the rows from your php results
console.log(arr);
// If your row has a field titled `question`, you can access it one of two ways:
alert(arr.question); // Object notation
alert(arr['question']); // Array notation
});
}
});