PHP merge arrays into 2D JSON

Question

I have 3 JSON strings coming in with POST and want to merge these into a 2 dimensional array and save in JSON format to the database. For this example I have image URL's, alt descriptions and booleans isfavorite

$url_arr = json_decode('["http://site.com/001.jpg","http://site.com/003.jpg","http://site.com/002.jpg"]');
$alt_arr = json_decode('["testing internat chars àèéìòóù stop","second description",""]'); // UTF-8 supported
$isFav_arr = json_decode('["true", "false", "false"]'); // strings need to be converted to booleans

// merge into 2 dimensional array
// $img_arr = array_merge($url_arr, $alt_arr, $isFav_arr); // doesn't work, just add's to the end
// ...

// save 2D JSON in database
$to_db = json_encode($img_arr);

you want the three arrays to be in an array, right? and you want to save the JSON of that in the database, right? — Gordon, Nov 02 '10 at 14:08

score 1 · Accepted Answer · edited May 23 '17 at 12:29

1

Just string concatenate:

$to_db = '[' 
       . '["http://site.com/001.jpg","http://site.com/003.jpg","http://site.com/002.jpg"]'
       . ',["testing int chars àèéìòóù stop","second description",""]'
       . ',["true", "false", "false"]'
       . ']';

Unless you want to work with the values in the Json string, you dont need any en/decoding. You can use http://www.jsonlint.com/ to validate it (removed jsonlint and print_r dumps to make some space)

edited May 23 '17 at 12:29

Community

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answered Nov 02 '10 at 14:12

Gordon

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mmm, yes I think so.. is this valid JSON? I mean I can json_decode() I need to be able to access for example 'alt for second image' ect. – FFish Nov 02 '10 at 14:15
I just tried echo print_r(json_decode($to_db)); but it returns 1?? Would it not be better something like [["001.jpg","descr 1",false],["002.jpg","descr 2",true]] – FFish Nov 02 '10 at 14:22
@FFish I am not sure I understand what you are asking. It is valid (after I added the missing commas) and if you want to shove the Json string to the DB then this should be the prefered way because decoding it is expensive. – Gordon Nov 02 '10 at 14:24
1

OK, got it now (just copied your snipped, without the comma correction) That's great! thanks so much :-) – FFish Nov 02 '10 at 14:28

score 1 · Answer 2 · answered Nov 02 '10 at 14:34

$url_arr = json_decode('["http://site.com/001.jpg","http://site.com/003.jpg","http://site.com/002.jpg"]'); $alt_arr = json_decode('["testing int chars àèéìòóù stop","second description",""]'); // UTF-8 supported $isFav_arr = json_decode('["true", "false", "false"]'); // strings need to be converted to booleans

$img_arr = array( "urls"=>$url_arr, "alts"=>$alts_arr, "favs"=>$isFav_arr
); $results = json_encode($img_arr);

// possibly you will need to clean up numeric indexes ... before building multydim array

this is also a good answer, but Gordon's solution saves json encoding as in my example I have them already encoded. cheers — FFish, Nov 02 '10 at 17:05

score 0 · Answer 3 · answered Nov 02 '10 at 14:07

0

The easy bit:

$img_arr = array();

for ($i=0; $i < sizeof($url_arr); $i++) {
    $img_arr[] = array($url_arr[$i], $alt_arr[$i], $isFav_arr[$i]);
}

Saving to the DB depends which DB type you're using. Look at examples using either mysql_query, or prepared statements (preferred).

answered Nov 02 '10 at 14:07

Matt

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escape running if you see a for loop with sizeof! long live precalculated array lenght – nerkn Nov 02 '10 at 14:39

PHP merge arrays into 2D JSON

3 Answers3

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