Question

I was having a question about making a 2D JSON string

Now I would like to know why I can’t access the following:

$json_str = '{"urls":["http://example.com/001.jpg","http://example.com/003.jpg","http://example.com/002.jpg"],"alts":["testing int chars àèéìòóù stop","second description",""],"favs":["true", "false", "false"]}';

$j_string_decoded = json_decode($json_str);
// echo print_r($j_string_decoded); // OK

// test get url from second item
echo j_string_decoded['urls'][1];
// Fatal error: Cannot use object of type stdClass as array

Answer 1

You are accessing it with array-like syntax:

echo j_string_decoded['urls'][1];

Whereas object is returned.

Convert it to array by specifying second argument to true:

$j_string_decoded = json_decode($json_str, true);

Making it:

$json_str = '{"urls":["http://site.com/001.jpg","http://site.com/003.jpg","http://site.com/002.jpg"],"alts":["testing int chars àèéìòóù stop","second description",""],"favs":["true", "false", "false"]}';

$j_string_decoded = json_decode($json_str, true);
echo j_string_decoded['urls'][1];

Or Try this:

$j_string_decoded->urls[1]

Notice the -> operator used for objects.

Quoting from Docs:

Returns the value encoded in json in
appropriate PHP type. Values true,
false and null (case-insensitive) are
returned as TRUE, FALSE and NULL
respectively. NULL is returned if the
json cannot be decoded or if the
encoded data is deeper than the
recursion limit.

http://php.net/manual/en/function.json-decode.php