我如何使用JS和AJAX发送数组

Question

I have multiple input fields where a user can fill in answers to the question, with JavaScript i put the user input into a array.

When I view the console log inside google chrome I see the array wil be made correct, after that I want to sent the array with AJAX to a another php page so that i can save the data into my database.

When i check my database the post result = "Array" :(

someone who can help me???

////// JavaScript and AJAX code :

if (isConfirm) {
    checkAnswers();
    $('input[id="answer"]').each(function() {
        allAnswers.push($(this).val());
        allAnswers.toString(); 
    });
    console.log(allAnswers);
    $.ajax({
        type: 'post',
        url: 'actions/save_questions.php',
        data: { 'answers': allAnswers }
    });
}

/////// PHP code :

<?php

$user_answer = $_POST['answers'];
$date = date('d-m-Y h:i:s');

$arr = array($user_answer);

$query = "INSERT INTO made_questions (lesson_id, user_answer, datum) VALUES ('1', '$arr', '$date')";
mysqli_query($conn,$query) or die (mysqli_error($conn));

?>

The output into my database is:

id: 27

lesson_id: 1

user_answer: Array <----- this is wrong :(

datum: 16-06-2016 08:12:32

Console log output:

["horse", "nocleu", "Geel", "This is my dog", "Guten tag", "Sun", "Aap", "Honger", "knol", "Cat"]

Someone who maybe can help me???

Thanks a lot!

Answer 1

.toString() and .join() do not modify the original variable . You need to either say:

allAnswers = allAnswers.toString();

OR

data: {'answers': allAnswers.toString()}

Additionally

If you want the values ", " separated rather than just "," which is what is returned by .toString() you can say:

allAnswers = allAnswers.join(", ");

OR

data: {'answers': allAnswers.join(", ");

Important:

It is important to note that your .each() loop will break if you use .toString() in that way.

Broken

$('input[id="answer"]').each(function(){
    allAnswers.push($(this).val());
    allAnswers = allAnswers.toString(); 
});

The above code will not work because after the first iteration, allAnswers will be a string, therefore, calling .push() will throw an exception because .push() is not a function of string .

Fixed

$('input[id="answer"]').each(function(){
    allAnswers.push($(this).val());  
});
allAnswers = allAnswers.toString();

This code fixes the issue by converting the array to a string after you are done appending values to the array.

Answer 2

if you want all questions saved in string format, you can use json_encode

<?php

    $user_answer = $_POST['answers'];
    $date = date('d-m-Y h:i:s');

    $ques = json_encode($user_answer);

    $query = "INSERT INTO made_questions (lesson_id, user_answer, datum) VALUES ('1', '$ques', '$date')";
        mysqli_query($conn,$query) or die (mysqli_error($conn));

?>

warning : your code is not safe !

Answer 3

在sql中将其串联之前，应将数组转换为字符串。

$arr = implode(",", $user_answer);