Echo/return an array in php - php

Im trying to query a database from a php file then return the results (userLOC of each row) to the calling Jquery function.
Calling Jquery:
$.post(url, data, function (data)
{
alert(data);
})
relavent PHP:
$sql = "Select * from location";
$result = mysql_query($sql);
$stack = array();
while($row = mysql_fetch_array($result))
{
array_push($stack, $row["userLOC"]);
}
return $stack;
The problem is that I cant return it correctly, if I "echo $stack" it does not work it says Im trying to convert the array to string. If I "echo $stack[0]" it will give me the first result in the array correctly so I know the values are being stored correctly (as are $stack[1], etc.) but this only sends the one value back. And if I "return $stack" as pictured nothing is alerted because nothing is echoed. How would I go about getting the whole array back so that I could iterate through and use them on the jquery side?

In PHP
$foo = array();
echo $foo;
will produce the literal string Array as output.
You need to convert your array into a string. Since you're dealing with a Javascript target, use JSON as the perfect means of doing so:
$foo = array('a', 'b', 'c', 'd', 'e');
echo json_encode($foo);
Then in your JS code:
$.get(...., function (data) {
alert(data[1]); // spits out 'b'
});
Just remember to tell jquery that you're expecting JSON output.

You need to wrap (serialize) the data in a way that can be transported to the client via HTTP and used to get the original data.
Usual container formats are XML and JSON. JSON is well suited for usage in JavaScript, so use the PHP function json_encode() and echo the result.

Youll want to use JSON!
Client-side:
jQuery.post(url, data, function( data ) {
//Data is already converted from JSON
}, "json");
Server-side:
return json_encode($stack);
Explanation
Hope this helps!

echo json_encode($stack); can help you
at jquery side use jQuery.parseJSON()

You need to convert the array to a JSON object like this : return json_encode($stack);

Just convert your array it to a JSON object and return it back to your JavaScript:
return json_encode($stack);

As others have said, you may wish to wrap the output using something like json:
echo json_encode($stack);
However, if you aren't looking for an output with the complexity of JSON formatting, you could just use implode() to output a comma separated list:
echo implode(',',$stack);

Related

read jquery array in php

i am trying to retrieve the value of array via post in php script.
var data = [];
table.rows({ selected: true }).every(function(index){
// Get and store row ID
data.push(this.data()[0]); //create a 1 dimensional array
});
//send data via ajax
$.ajax({
url: '/...../...',
type: 'POST',
data: {userid:data},
dataType: 'json',
In my PHP script so far I am unable to decode the array. Have tried many ways
$myArray = $_REQUEST['userid'];
foreach ($arr as $value) {
$userid= $value; //for now just trying to read single item
}
I have tried print_r($myArray ); this sucessfully prints array contents to screen.
I am trying to retrieve the values for processing! Kindly point me in the right direction
I don't think that PHP would recognise the array that you've called "data" as being an array. Couldn't you turn the data from your table rows into values in a JavaScript object, encode it as a JSON string, then post that to your PHP script and use json_decode($_POST["userid"]) on the PHP end to convert it into a PHP array.
The object you are posting to PHP isn't in particular a jQuery object. Instead it is an JSON object or rather a JSON string. I guess you can't read that object the way you would read an regular array in PHP.
You might want to try to decode the string with json_decode(). With true as an function argument, it will return an php array as suggested in this stackoverflow answer https://stackoverflow.com/a/6964549/6710876
$phpArray = json_decode($myArray, true);
Documentation of json_decode(): http://php.net/manual/en/function.json-decode.php
simply use:
echo json_encode($myArray);
You're foreach is looping $arr, which doesn't exist. Your array is being set to $myArray, so use that in your for.
$myArray = $_REQUEST['userid'];
foreach ($myArray as $value) {
$userid= $value; //for now just trying to read single item
}
I believe you should also be able to find your values in $_POST
According to your var_dump :
array(1) { ["userid"]=> string(21) "assssssss,camo,castor" }
and if we assume "assssssss,camo,castor" are 3 different usernames.
You should use this:
$userids=explode(",",$myArray->userid);
foreach($userids as $userid){
// use $userid
}

Populate JS array from returned PHP/JSON

I have a JSON encoded array, to which i am returning to an AJAX request.
I need to place the JSON array into a JS Array so i can cycle through each array of data to perform an action.
Q. How do i place the JSON array contents into a JS array efficiently?
The PHP/JSON Returned to the AJAX
$sql = 'SELECT *
FROM btn_color_presets
';
$result = mysqli_query($sql);
$array = array(); //
while($row = mysql_fetch_assoc($result)) //
{
$array[] = $row;
$index++;
}
header("Content-type: application/json");
echo json_encode($array);
You can use JSON.parse function to do so:
var myObject = JSON.parse(response_from_php);
// loop over each item
for (var i in myObject) {
if (myObject.hasOwnProperty(i)) {
console.log(myObject[i]);
}
}
You can also use jQuery.parseJSON() if you are using jQuery, however jQuery also uses same function under the hood as priority if available.
Adding to Safraz answer:
If you're using jQuery, there's another way to do that. Simply add json as last parameter to your ajax calls. It tells jQuery that some json content will be returned, so success function get already parsed json.
Below example shows you simple way to achieve this. There's simple json property accessing (result.message), as well as each loop that iterates through whole array/object. If you will return more structurized json, containing list of object, you can access it inside each loop calling value.objectfield.
Example:
//Assuming, that your `json` looks like this:
{
message: 'Hello!',
result: 1
}
$.post(
'example.com',
{data1: 1, data2: 2},
function(response){
console.log(response.message) //prints 'hello'
console.log(response.result) //prints '1'
//iterate throught every field in json:
$(response).each(function(index, value){
console.log("key: " + index + " value: " + value);
});
},
'json'
)

json encoding 2 dimension array

I have the following in php:
$query = mysql_query($sql);
$rows = mysql_num_rows($query);
$data['course_num']=$rows;
$data['course_data'] = array();
while ($fetch = mysql_fetch_assoc($query) )
{
$courseData = array(
'course_name'=>$fetch['course_name'],
'training_field'=>$fetch['training_field'],
'speciality_field'=>$fetch['speciality_field'],
'language'=>$fetch['language'],
'description'=>$fetch['description'],
'type'=>$fetch['type'],
);
array_push($data['course_data'],$courseData);
}
echo json_encode($data);
when I receive the result of this script in jquery (using post)
I log it using :
console.log(data['course_data']);
and the output is :
[Object { course_name="Introduction to C++", training_field="Engineering" , speciality_field="Software", more...}]
But I can't seem to figure out how to access the elements.
I tried
data['course_data'].course_name
data['course_data']['course_name']
Nothing worked. Any ideas
When you array_push($data['course_data'],$courseData); you are actually putting $courseData at $data['course_data'][0] and therefore you would access it in JavaScript as data['course_data'][0]['course_name'].
If you only intend to have one result, instead of array_push($data['course_data'],$courseData); you should just specify $data['course_data'] = $courseData. Otherwise, you should iterate over data['course_data'] like so:
for (i in data['course_data']) {
console.log(data['course_data'][i]['course_name']);
}
You should specify the index in the first array for instance
data['course_data'][0]['course_name'];
you could make it better if you had defined the first array just as variable not a variable within an array
$data['course_data'][0]['course_name']
should do the trick. If not please send the output of var_dump($data)
Assuming the PHP code is correct, you will receive a JSON data like:
{
"course_num":34,
"course_data":[
{
"course_name":"name_value",
....
},
....etc (other object based on SQL result)
]
}
So, if you want to access to the total number of result:
data.course_num
If you want to access to the first element of the list of result:
data.course_data[0]
If you want to access to the name of the first element of the list of result:
data.course_data[0].course_name
or
data.course_data[0]['course_name']
use jquery's parseJSON method to get all the goodies out of the json object...
http://api.jquery.com/jQuery.parseJSON/

Make JSON array Flot compatible

I have some PHP code that outputs a JSON array when $.getJSON is called:
.
.
.
$data = array_combine($date_dispatched,$amount);
echo json_encode($data);
This is collected by:
$.getJSON('statistics_get.php',function(output) {
$.plot($("#graph_1"), [{
data: output,
lines: {show:true}
}]
);
});
Now, using firebug, the response I get back is of the form:
{"0":"0","1296658458000":"566","1296725534000":"789","1297072385000":"890","1297072388000":"435"}
Flot is not processing this data. I believe Flot needs it to be in the form [[1,2],[4,5],[6,9]] etc. So my question is, what is the best way of getting this JSON array into the correct form for flot to read and produce a graph.
If you look at example two here: http://php.net/manual/en/function.json-encode.php
you will see that you can have json_encode return an array instead of an associative object
Would that not be the solution rather than
var flotArr = []
var cnt=0;
for (var o in data) flotArr[cnt++]=[o,data[o]]
Don't use array_combine, since it doesn't do what you need. Doing "zip" in PHP is a little bit unpleasant, but you should be able to manage with:
function make_pair($date, $amount) {
return array($date, $amount);
}
$data = array_map('make_pair', $date_dispatched, $amount);
And then JSON-encode that.

php json_encode doesn't result in real object / make array string into real object / turn php array into json

Here is my PHP code, it's getting a listing of collections from mongodb
$list = $db->dbname->listCollections();
$result = array();
$i=0;
foreach ($list as $thiscollection) {
$result[$i++] = $thiscollection->getName();
}
echo json_encode( $result );
I do console.log in the callback and this is what I see.
["fruits", "dogs", "cars", "countries"]
The problem is that this is a string, not an array. I need to iterate through these values. How an I make this into a real object or get php to give me json rather than php array so I can use parseJSON on it.
Thanks.
js:
$.post('/ajax-database.php', function (data) {
console.log($.parseJSON(data));
$.each(data, function (key, value) {
console.log(value);
});
});
I see you are using jquery, if you want data to come back to you as a json object you need to do 1 of 2 things.
add header("Content-Type: application/json") to your php file, this will tell jquery to convert it to a json object instead of as text
Add a forth parameter to your $.post,
$.post('/ajax-database.php', function (data) {
console.log($.parseJSON(data));
$.each(data, function (key, value) {
console.log(value);
});
}, "json");
that will tell jquery to call your error handler if its NOT json, like if your php code fails and outputs html instead. You really should use $.ajax, i have no idea why anyone uses $.post, you can't do ANY meaningful error handling.
JSON is strings. If you want to be able to iterate over it then you need to decode it.

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