Creating a JavaScript array from PHP – square brackets and curly braces

Question

I am trying to pass code from my PHP backend to the google-chart JavaScript API. I have had success using PHP’s json_encode(), for passing arrays of numbers and strings. For simple data arrays json_encode() works just fine:

<?php $data = [['Series1', 'Series2'], [0, 1], [2, 3], [3, 4]]; />

<script>
var data = <?php echo(json_encode($data));?>;
</script>

But, the Google Charts API requires that row-parameters be passed as objects in {curly braces}.

Here is the JavaScript array I am trying to produce:

var data = [
    ['Genre', 'Fantasy & Sci Fi', 'Romance', 'Mystery/Crime', 'General',
     'Western', 'Literature', { role: 'annotation' } ],
    ['2010', 10, 24, 20, 32, 18, 5, ''],
    ['2020', 16, 22, 23, 30, 16, 9, ''],
    ['2030', 28, 19, 29, 30, 12, 13, '']
];

The trouble is producing the {role: 'annotation'} bit in PHP. Any suggestions?

You do not `JSON.parse()` JSON text when it is outputted directly in ` — Patrick Evans, May 23 '16 at 22:01
Oh, you're right. I don't have that in there. I was going from memory and forgot that I didn't need that bit. I edited the question. — Christopher Culbreath, May 23 '16 at 22:02
Possible duplicate of [PHP : Create array for JSON](http://stackoverflow.com/questions/6739871/php-create-array-for-json) — miken32, May 23 '16 at 23:36

score 4 · Accepted Answer · answered May 23 '16 at 22:01

4

This should do the trick:

$data = [['Series1', 'Series2', ['role'=>'annotation']], [0, 1], [2, 3], [3, 4]];

You can create objects in php by creating a new stdClass, but an dictionary (key => value array) is converted to JSON the same way (with curly brackets). This would work as well:

$object = new stdClass();
$object->role = 'annotation';

$data = [['Series1', 'Series2', $object], [0, 1], [2, 3], [3, 4]];

answered May 23 '16 at 22:01

Erik Terwan

2,710
19
28

That seems to have worked! I thought I tried that earlier, but must have made a mistake. Thanks for your help! – Christopher Culbreath May 23 '16 at 22:06
Nice! If it worked, it's good practice to mark the answer as correct (by hitting the green checkmark next to the counter) – Erik Terwan May 23 '16 at 22:52

score 0 · Answer 2 · answered May 23 '16 at 22:03

0

You can create an object in PHP and json_encode will create an object from that:

$myObj = new stdClass;
$myObj->role = "annotation";

Then 'json_encode($myObj);' will return the JSON object you want.

answered May 23 '16 at 22:03

swatkins

13,530
4
46
78

Creating a JavaScript array from PHP – square brackets and curly braces

2 Answers2