通过JSON将javascript数组发送到php不起作用

Question

I have a javascript array and want to send it to the php via form input hidden field. What i'm doing is here:

html:

<form method="post" action="a.php" onSubmit="fun();">
    <input type="hidden" name="hiddenF" value="">
</form>

and in javascript:

function fun()
{
    var jArray = [ "One", "Two", "Three"];

    document.getElementsByName("hiddenF").value = JSON.stringify(jArray);
}

and finally in php that i need an array doing like below but i don't get anything on page.

$arr=json_decode($_POST['hiddenF']);
print_r($arr);

Answer 1

document.getElementsByName("hiddenF") returns an array. So you need to add [0] to access your hidden input.

Should be like that:

document.getElementsByName("hiddenF")[0].value = JSON.stringify(jArray);

Answer 2

You can also do it by using ID attribute..This will work

<?php
if(isset($_POST["submit"])){
    $arr = json_decode($_POST['hiddenF']);
    print_r($arr);
}
?>

<script type="text/javascript">
function fun()
{
    var jArray = [ "One", "Two", "Three"];
    document.getElementById("hiddenF").value = JSON.stringify(jArray);
}

</script>

<form method="post" action="<?=$_SERVER["PHP_SELF"]?>" onSubmit="fun();">
    <input type="hidden" name="hiddenF" value="" id="hiddenF">
    <input type="submit" name="submit" />
</form>

If you want to make it work with name attribute, go with above answers.

Answer 3

The function document.getElementsByName return an array, so you can't change the .value of this array.

// ...
document.getElementsByName("hiddenF")[0].value = JSON.stringify(jArray);

But I suggest you to use getElementById instead.

HTML:

<input type="hidden" id="hiddenF" name="hiddenF" value="">

JS:

// ...
document.getElementById("hiddenF").value = JSON.stringify(jArray);

Answer 4

Try this:

Java Script:

function fun(){
    var jArray = [ "One", "Two", "Three"];
    document.getElementsByName("hiddenF")[0].value = JSON.stringify(jArray);    
}

Html Form:

<form method="post" action="process.php" onSubmit="return fun();">
    <input type="hidden" name="hiddenF" value="">
    <input type="submit" value="Submit"/>
</form>

Process.php

<?php
$arr=json_decode($_POST['hiddenF']);
print_r($arr);
?>