PHP Prepend two elements to associative array

Question

I have the following array, I'm trying to append the following ("","--") code

Array
(
    [0] => Array
        (
            [Name] => Antarctica
        )

)

Current JSON output

[{"Name":"Antarctica"}]

Desired output

{"":"--","Name":"Antarctica"}]

I have tried using the following:

$queue = array("Name", "Antarctica");
array_unshift($queue, "", "==");

But its not returning correct value.

Thank you

$queue = array("Name", "Antarctica"); is not the same as what you show at the beginning of the question. — gen_Eric
– gen_Eric, Commented Jan 9, 2015 at 20:39
If Your goal is to create such JSON, You should know that JSON objects are unordered lists of key-value pairs, so the effort would be senseless. See json.org - "An object is an unordered set of name/value pairs.". — Roman Hocke
– Roman Hocke, Commented Jan 9, 2015 at 20:43

BrokenBinary · Accepted Answer · 2015-01-09 20:39:02Z

4

You can prepend by adding the original array to an array containing the values you wish to prepend

$queue = array("Name" => "Antarctica");
$prepend = array("" => "--");
$queue = $prepend + $queue;

You should be aware though that for values with the same key, the prepended value will overwrite the original value.

answered Jan 9, 2015 at 20:39

BrokenBinary

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1 Comment

Mouser Over a year ago

This doesn't make any changes to the array's numerical index too. If it had any. Nice.

LSerni · Accepted Answer · 2015-01-09 20:46:03Z

The translation of PHP Array to JSON generates a dictionary unless the array has only numeric keys, contiguous, starting from 0.

So in this case you can try with

$queue = array( 0 => array( "Name" => "Antarctica" ) );

$queue[0][""] = "--";

print json_encode($queue);

If you want to reverse the order of the elements (which is not really needed, since dictionaries are associative and unordered - any code relying on their being ordered in some specific way is potentially broken), you can use a sort function on $queue[0], or you can build a different array:

$newqueue = array(array("" => "--"));
$newqueue[0] += $queue[0];

which is equivalent to

$newqueue = array(array_merge(array("" => "--"), $queue[0]));

This last approach can be useful if you need to merge large arrays. The first approach is probably best if you need to only fine tune an array. But I haven't ran any performance tests.

Tim Lewis · Accepted Answer · 2015-01-09 20:45:43Z

1

Try this:

$queue = array(array("Name" => "Antarctica")); // Makes it multidimensional 
array_unshift($queue, array("" => "--"));

Edit

Oops, just noticed OP wanted a Prepend, not an Append. His syntax was right, but we was missing the array("" => "--") in his unshift.

edited Jan 9, 2015 at 20:45

answered Jan 9, 2015 at 20:37

Tim Lewis

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Comments

yuriy.stos · Accepted Answer · 2015-01-09 20:40:58Z

0

You can try this :

$queue = array("Name" => "Antarctica");
$result = array_merge(array("" => "=="), $queue);

answered Jan 9, 2015 at 20:40

yuriy.stos

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2 Comments

LSerni Over a year ago

No, this only generates a single dictionary, not an array of one dictionary. You can use $result=array(array_merge...); though.

yuriy.stos Over a year ago

You are totally right:) Not fully understand this problem.@Iserni

litechip · Accepted Answer · 2015-01-09 20:42:22Z

0

var_dump(array_merge(array(""=>"--"), $arr));

answered Jan 9, 2015 at 20:42

litechip

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