Generate json string from multidimensional array data [duplicate] - php

Question

This question already has answers here:
How to create an array for JSON using PHP?
(8 answers)
Closed 1 year ago.
I am using a plugin that requires an array of associative rows as a json formatted string -- something like:
[
{oV: 'myfirstvalue', oT: 'myfirsttext'},
{oV: 'mysecondvalue', oT: 'mysecondtext'}
]
How do I convert my multidimensional array to valid JSON output using PHP?

Answer 1

Once you have your PHP data, you can use the json_encode function; it's bundled with PHP since PHP 5.2.
In your case, your JSON string represents:
a list containing 2 elements
each one being an object, containing 2 properties/values
In PHP, this would create the structure you are representing:
$data = array(
(object)array(
'oV' => 'myfirstvalue',
'oT' => 'myfirsttext',
),
(object)array(
'oV' => 'mysecondvalue',
'oT' => 'mysecondtext',
),
);
var_dump($data);
The var_dump gets you:
array
0 =>
object(stdClass)[1]
public 'oV' => string 'myfirstvalue' (length=12)
public 'oT' => string 'myfirsttext' (length=11)
1 =>
object(stdClass)[2]
public 'oV' => string 'mysecondvalue' (length=13)
public 'oT' => string 'mysecondtext' (length=12)
And, encoding it to JSON:
$json = json_encode($data);
echo $json;
You get:
[{"oV":"myfirstvalue","oT":"myfirsttext"},{"oV":"mysecondvalue","oT":"mysecondtext"}]
By the way, from what I remember, I'd say your JSON string is not valid-JSON data: there should be double-quotes around the string, including the names of the objects' properties.
See http://www.json.org/ for the grammar.

Answer 2

The simplest way would probably be to start with an associative array of the pairs you want:
$data = array("myfirstvalue" => "myfirsttext", "mysecondvalue" => "mysecondtext");
then use a foreach and some string concatenation:
$jsontext = "[";
foreach($data as $key => $value) {
$jsontext .= "{oV: '".addslashes($key)."', oT: '".addslashes($value)."'},";
}
$jsontext = substr_replace($jsontext, '', -1); // to get rid of extra comma
$jsontext .= "]";
Or if you have a recent version of PHP, you can use the json encoding functions built in - just be careful what data you pass them to make it match the expected format.

Answer 3

This is one of the most fundamental rules in php development:
DO NOT MANUALLY BUILD A JSON STRING.
USE json_decode().
If you need to populate your data in a loop, then gather all of your data first, then call json_encode() just once.
Do not try to wrap/prepend/append additional data to an encoded json string. If you want to add data to the json payload, then decode it, add the data, then re-encode it.
It makes no difference if you pass object type or array type data to json_encode() -- by default, it will still create a string using square braces for indexed arrays and curly braces for iterable data with non-indexed keys.
Code:
$array = [
[
'oV' => 'myfirstvalue',
'oT' => 'myfirsttext'
],
[
'oV' => 'mysecondvalue',
'oT' => 'mysecondtext'
]
];
echo json_encode($array);
Output:
[{"oV":"myfirstvalue","oT":"myfirsttext"},{"oV":"mysecondvalue","oT":"mysecondtext"}]
For clarity, I should express that the OP's desired output is not valid json because the nested keys are not double quote wrapped.

Answer 4

You can use the stdClass, add the properties and json_encode the object.
$object = new stdClass();
$object->first_property = 1;
$object->second_property = 2;
echo '<pre>';var_dump( json_encode($object) , $object );die;
Voilà!
string(40) "{"first_property":1,"second_property":2}"
object(stdClass)#43 (2) {
["first_property"]=>
int(1)
["second_property"]=>
int(2)
}

Answer 5

This is the php code to generate json format.
while ($row=mysqli_fetch_assoc($result))
{
$array[] = $row;
}
echo '{"ProductsData":'.json_encode($array).'}'; //Here ProductsData is just a simple String u can write anything instead