Array of associative arrays, add new elements to the associative arrays [duplicate] - php

Question

This question already has answers here:
How to modify an array's values by a foreach loop?
(2 answers)
Closed 4 months ago.
If I have an array like this:
array(2) {
[0]=>
array(2) {
["id"]=>
string(2) "34"
["total"]=>
string(6) "122337"
},
[1]=>
array(2) {
["id"]=>
string(2) "43"
["total"]=>
string(6) "232337"
}
}
And I want to add a new key value to each sub array, so for example, it would end like this:
array(2) {
[0]=>
array(2) {
["id"]=>
string(2) "34"
["total"]=>
string(6) "122337"
["newkey"]=>
string(6) "hihihi"
},
[1]=>
array(2) {
["id"]=>
string(2) "43"
["total"]=>
string(6) "232337"
["newkey"]=>
string(6) "hihihi"
}
}
How would I do it?
I have tried with a foreach like this:
foreach($exterior_array as $inside_array) {
$inside_array['newkey'] = "hihihi";
}
But once I get inside the foreach, the values are not saved.

Answer 1

foreach($exterior_array as $inside_array) {
$inside_array['newkey'] = "hihihi";
}
But once I get inside the foreach, the values are not saved.
That is because you are working on a copy of the array via $inside_array. You can access the "orignal" value you want to change by making $inside_array an alias of the origina value; using a reference:
foreach($exterior_array as &$inside_array) {
^- set the reference
$inside_array['newkey'] = "hihihi";
}
unset($inside_array);
^^^^^^^^^^^^^^^^^^^^^- remove the reference
Compare with http://php.net/foreach

Answer 2

foreach($exterior_array as $k=>$inside_array) {
$exterior_array[$k]['newkey'] = "hihihi";
}
try this

Answer 3

foreach($exterior_array as $key => $inside_array) {
$inside_array[$key]['newkey'] = "hihihi";
}

Answer 4

Another solution using references:
foreach($exterior_array as &$inside_array) {
$inside_array['newkey'] = "hihihi";
}

Answer 5

Because you are using it as a temporary array, do it like this:
foreach($exterior_array as $key => $inside_array)
{
$exterior_array[$key]['newkey'] = "hihihi";
}
Or you can do it with references as jpo suggested, this will make a new array, but keep it linked to the original (note the &):
foreach($exterior_array as &$inside_array)
{
$inside_array['newkey'] = "hihihi";
}

Answer 6

Try this. Tested and verified.
<?php
$parentArray = array(
array("id"=>1),
array("id"=>2),
array("id"=>3),
);
foreach($parentArray as $key=>$childArray)
{
$parentArray[$key]['newkey'] = "hello";
}
//output
Array
(
[0] => Array
(
[id] => 1
[newkey] => hello
)
[1] => Array
(
[id] => 2
[newkey] => hello
)
[2] => Array
(
[id] => 3
[newkey] => hello
)
)
?>

Answer 7

Its not a perfect fit for this topic, but I used this a lot in my own projects.
http://pastebin.com/TyWzLWuK
Its not very performant but easy to handle.
Example:
Fw_Recursive_Array_Helper::set($array, '0.someKey.someSubKey', 'value');
if(Fw_Recursive_Array_Helper::has($array, '0.someKey.someSubKey')) {
echo Fw_Recursive_Array_Helper::get($array, '0.someKey.someSubKey');
}
echo Fw_Recursive_Array_Helper::get($array, '1.someKey.someSubKey', 'If the key does not exist, use this');

Answer 8

class helper
{
public function arrayInsert($key=NULL,$value=NULL,& $array=array())
{
if(!empty($key)&&!empty($value)&&is_array($array))
{
$array[$key]=$value;
}
}
}
$obj=new helper();
$array=array('1'=>1,'a'=>'a');
$obj->arrayInsert('b','b',$array);
print_r($array)
o/p=>Array ( [1] => 1 [a] => a [b] => b )