PHP Checkboxes in an array - php

Question

When a form gets posted, I get some checkbox values like the below:
Array ( [chk0] => true ,
[chk1] => true,
[chk3] => true,
[chk1002] => on,
[chk1005] => on
)
Using PHP,How can I construct a JSON request like this by using the above variables?
"data":
[
{
"checkboxval": true,
"id": 0
},
{
"checkboxval": true,
"id": 1
},
{
"checkboxval": true,
"id": 3
},
{
"checkboxval": true,
"id": 1002
},
{
"checkboxval": true,
"id": 1005
}
]
Please note that my POST variables can have other form variables too, but all checkbox values will be named with the prefix "chk"

Answer 1

$output = array();
foreach ($input as $k => $v) {
$output[] = array(
'checkboxval' => !!$v,
'id' => preg_replace('!^chk!', '', $k),
);
}
header('Content-Type: application/json');
echo json_encode(array('data' => $output));

Answer 2

foreach ($_POST as $k => $v) {
$output[] = array(
'checkboxval' => ($v=='on'? true : ($v=='off' ? false : !!$v)),
'id' => preg_replace('!^chk!', '', $k),
);
}
header('Content-Type: application/json');
echo json_encode(array('data' => $output));
Credits to cletus who provided the basis for this code.

Answer 3

Have a look at the json_encode() php function. You'll have to massage your array a little to get the exact JSON format you're after.

Answer 4

Heres an example...
$_POST["chk1"] = "Hello";
$_POST["chk2"] = "World";
$jsonArray = array();
foreach($_POST as $key => $val){
if(preg_match("/chk/", $key)){
$jsonArray[$key] = $val;
}
}
$jsonArray = array("Data" => $jsonArray);
$json = json_encode($jsonArray);
echo "<pre>";
echo $json;
echo "</pre>";
Outputs this:
{"Data":{"chk1":"Hello","chk2":"World"}}

Answer 5

I haven't tested this yet, but maybe something like this:
$json = '"data": [';
$first = true;
foreach ($_POST as $k => $v){
if (preg_match('/^chk(\d+)$/', $k, $m)){
if ($first) $first = false; else $json .= ", ";
$json .= sprintf('{ "checkboxval" : %s, "id" : %s }', ($v && $v != "off") ? "true" : "false", $m[1]);
}
}
$json .= ']';