Json Parsing error using JSON.parse() - php

Question

I have developed an api which will post some data in json format to be used in an android app. However I am getting json parsing error. I am new to this whole json thing so unable to understand what the error means.
This is my json encoded output that the php backend generates
{
"data": [
{
"id": "2",
"name": "Rice",
"price": "120",
"description": "Plain Rice",
"image": "6990_abstract-photo-2.jpg",
"time": "12 mins",
"catagory": "Lunch",
"subcat": ""
}
]
}{
"data": [
{
"id": "4",
"name": "Dal",
"price": "5",
"description": "dadadad",
"image": "",
"time": "20 mins",
"catagory": "Dinner",
"subcat": ""
}
]
}{
"data": [
"catagory": "Soup"
]
}
This is the error the online json parser gives
SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 2 column 1 of the JSON data
What is actually wrong here? Could you please provide me with the correct json output for the following data?

Answer 1

This should clear it up
$main = array();
while($row = $result->fetch(PDO::FETCH_ASSOC)){
$cat = $row['category'];
$query1 = "SELECT * FROM item WHERE catagory='$cat'"; //Prepare login query
$value = $DBH->query($query1);
if($row1 = $value->fetch(PDO::FETCH_OBJ))
{
$main[] = array('data'=>array($row1));
}
else
{
$main[] = array('data'=>array('catagory'=>$row['category']));
}
}
echo json_encode($main);

Answer 2

You shouldn't create your json string by hand. Create your array structure, then finally invoke json_encode() at the end.
$data = array();
try
{
$query = "SELECT category FROM category"; // select category FROM category? what?
$result= $DBH->query($query);
while($row = $result->fetch(PDO::FETCH_ASSOC)){
$cat = $row['category'];
$query1 = "SELECT * FROM item WHERE catagory='$cat'";
$value = $DBH->query($query1);
if($value->rowCount() > 0) {
$data[] = array('data' => $value->fetch(PDO::FETCH_ASSOC));
}
else {
$sub = array('category' => $row['category']);
$data[] = array('data' => $sub);
}
}
$result->closeCursor();
$DBH = null;
echo json_encode($data); // encode at the end
}
catch(PDOException $e)
{
print $e->getMessage ();
die();
}