PHP: Turning multidimensional arrays to single dimension arrays - php

Basically my app is interacting with a web service that sends back a weird multidimensional array such as:
Array
(
[0] => Array
(
[Price] => 1
)
[1] => Array
(
[Size] => 7
)
[2] => Array
(
[Type] => 2
)
)
That's not a problem, but the problem is that the service keeps changing the index of those items, so in the next array the Price could be at 1 instead of 0.
How do I effeciently transform arrays like this into a single dimension array so I can access the variables through $var['Size'] instead of $var[1]['Size']?
Appreciate your help

$result = call_user_func_array('array_merge', $array);

Like this:
$result = array();
foreach($array as $inner) {
$result[key($inner)] = current($inner);
}
The $result array would now look like this:
Array
(
[Price] => 1
[Size] => 7
[Type] => 2
)

I am using laravel's helper: http://laravel.com/api/source-function-array_flatten.html#179-192
function array_flatten($array)
{
$return = array();
array_walk_recursive($array, function($x) use (&$return) { $return[] = $x; });
return $return;
}

function flattenArray($input, $maxdepth = NULL, $depth = 0)
{
if(!is_array($input)){
return $input;
}
$depth++;
$array = array();
foreach($input as $key=>$value){
if(($depth <= $maxdepth or is_null($maxdepth)) && is_array($value)){
$array = array_merge($array, flattenArray($value, $maxdepth, $depth));
} else {
array_push($array, $value);
// or $array[$key] = $value;
}
}
return $array;
}

Consider $mArray as multidimensional array and $sArray as single dimensional array this code will ignore the parent array
function flatten_array($mArray) {
$sArray = array();
foreach ($mArray as $row) {
if ( !(is_array($row)) ) {
if($sArray[] = $row){
}
} else {
$sArray = array_merge($sArray,flatten_array($row));
}
}
return $sArray;
}

I think i found best solution to this : array_walk_recursive($yourOLDmultidimarray, function ($item, $key) {
//echo "$key holds $item\n";
$yourNEWarray[]=$item;
});

If you use php >= 5.6, you may use array unpacking (it's much faster):
$result = array_merge(...$array);
See wiki.php.net on unpacking

Related

Flatten multidimensional array of numbers recursively

Let's say I have an array like this
Array
(
[0] => 123
[180] => Array
(
[400] => Array
(
[0] => 474
[1] => 395
[2] => 994
[3] => 365
)
)
[1] => 144
[2] => 119
)
I would like to go though this array and generate a one dimensional array that contains all the numbers. In the loop, if we get an array, then the number is the corresponding array key.
I did something like this but it doesn't work:
function flatten_array($data) {
$result = array();
foreach ($data as $key => $value) {
if(is_array($value)) {
$result[] = $key;
flatten_array($value);
} else {
$result[] = $value;
}
}
return $result;
}
The resulting array I should get should be this one:
$result = Array
(
[0] => 123
[1] => 180
[2] => 400
[3] => 474
[4] => 395
[5] => 994
[6] => 365
[7] => 144
[8] => 119
)
Any help will be appreciated thanks.
There are some helpful libraries in composer, for example this one: https://packagist.org/packages/nikic/iter
With this lib you can flatten the data the following way:
$result = toArray(flatten($data));
Without using libraries, such result can be achieved this way:
function flattenArray(array $data) {
$values = array_values($data);
$result = [];
foreach ($values as $value) {
if (is_array($value)) {
$result = array_merge(flattenArray($value), $result);
} else {
$result[] = $value;
}
}
return $result;
}
P.S. Note the mistake in your original example:
$result[] = $key;
flatten_array($value);
You call the recursive function without using its returned result.
And you assign the key instead.
Your code doesn't accumulate a result anywhere. You could return arrays and merge them, but to save allocation overhead I recommend using a single result array and passing it by reference into your recursive walk function. Here's a complete example:
function flatten_array($a) {
function flatten($a, &$flat) {
foreach ($a as $k => $v) {
if (is_array($v)) {
$flat[] = $k;
flatten($v, $flat);
}
else {
$flat[] = $v;
}
}
}
$flat = [];
flatten($a, $flat);
return $flat;
}
$a = [
123,
180 => [
400 => [
474,
395,
994,
365,
]
],
144,
119
];
print_r(flatten_array($a));
If you expect your depth to be massive, you can do it iteratively to avoid an overflow. Note that this gives a breadth-first ordering:
function flatten_array($a) {
$flat = [];
for ($stack = [$a]; count($stack);) {
foreach (array_pop($stack) as $k => &$v) {
if (is_array($v)) {
$flat[] = $k;
$stack[] = $v;
}
else {
$flat[] = $v;
}
}
}
return $flat;
}
You can use next recursive function:
function array_flat($arr) {
$res = [];
foreach($arr as $key=>$val) {
if (is_array($val)) {
// element is array: Push key to result and merge recursion result
array_push($res, $key);
$res = array_merge($res, array_flat($val));
} else {
// push simple value to result
array_push($res, $val);
}
}
return $res;
}
print_r(array_flat($arr));
Try working PHP code o PHPize.online

How can I call particular array value of array in php?

I'm getting below output as an array.
$array =
Array
(
[12] => Array
(
[1] => Array
(
[14] => Array
(
[0] => Array
(
[name] => Avaya Implementation Services
[service_id] => 14
[ser_type_id] => 1
[service_desc] =>Avaya Implementation Servic
)
)
)
)
);
I want to print only service_desc array value. and I don't want call like $array[12][1][14][0]['service_desc'];
How can I call particular service_desc array value of the array?
As you mentioned that you don't want to call it as $array[12][1][14][0]['service_desc'] you can use extract function which will create variables from your array,
extract($array[12][1][14][0]);
echo $service_desc;
And then you can use your particular key such as service_desc as variable.
You can try this function: (Please optimize as per your requirements)
$arr ="<YOUR ARRAY>";
$val = "service_desc";
echo removekey($arr, $val);
function removekey($arr, $val) {
$return = array();
foreach ($arr as $k => $v) {
if (is_array($v) && $k !== $val) {
removekey($v, $val);
continue;
}
if ($k == $val) {
echo ($arr[$k]);
die;
}
$return[$k] = $v;
}
return $return;
}
You can use array_walk_rescursive to frame a single dimensional array of matching keys:
DEMO
<?php
$array[12][1][14][0]['service_desc'] = 'Avaya Implementation Servic';
$array[12][1][14][0]['service'] = 'dsfasf';
$array[12][1][114][0]['service_desc'] = 'Avaya Implementation Servicasdfdsf';
$searchKey = 'service_desc';
$desiredValues = [];
array_walk_recursive($array, function ($v, $k) use ($searchKey, &$desiredValues) {
if ($k === $searchKey) {
$desiredValues[] = $v;
}
});
print_r($desiredValues);
So this will yield:
Array
(
[0] => Avaya Implementation Servic
[1] => Avaya Implementation Servicasdfdsf
)
You might use the array_walk_recursive function.
array_walk_recursive($array, function ($val, $key) {
if ($key == 'service_desc') print_r($val);
} );
Instead of the print_r statement, you can collect your data into another structure, which you convey using the use statement, or with the $userdata additional parameter (see http://www.php.net/manual/en/function.array-walk-recursive.php ).
$results = array();
array_walk_recursive($array, function ($val, $key) use (&$results) {
if ($key == 'service_desc') {
$results []= $val;
}
} );
Pay extra care to the & in front of the use (&$results) otherwise your array of results will be considered immutable inside the callback (i.e. all changes discarded).
Convert multidimensional array to single array using iterator_to_array
REF: http://php.net/manual/en/function.iterator-to-array.php
$service_desc= iterator_to_array(new RecursiveIteratorIterator(new RecursiveArrayIterator($your_array)), 0);
print_r($service_desc);
Result:
Array
(
[name] => Avaya Implementation Services
[service_id] => 14
[ser_type_id] => 1
[service_desc] =>Avaya Implementation Servic
)

Implode an inner array values

An array
Array
(
[0] => Array
(
[Detail] => Array
(
[detail_id] => 1
)
)
[1] => Array
(
[Detail] => Array
(
[detail_id] => 4
)
)
)
Is it possible to use implode function with above array, because I want to implode detail_id to get 1,4.
I know it is possible by foreach and appending the array values,
but want to know whether this is done by implode function or any other inbuilt function in PHP
What about something like the following, using join():
echo join(',', array_map(function ($i) { return $i['Detail']['detail_id']; }, $array));
If you need to use some logic - then array_reduce is what you need
$result = array_reduce($arr, function($a, $b) {
$result = $b['Detail']['detail_id'];
if (!is_null($a)) {
$result = $a . ',' . $result;
}
return $result;
});
PS: for php <= 5.3 you need to create a separate callback function for that
Please check this answer.
$b = array_map(function($item) { return $item['Detail']['detail_id']; }, $test);
echo implode(",",$b);
<?php
$array = array(
array('Detail' => array('detail_id' => 1)),
array('Detail' => array('detail_id' => 4)),);
$newarray = array();
foreach($array as $items) {
foreach($items as $details) {
$newarray[] = $details['detail_id'];
}
}
echo implode(', ', $newarray);
?>

Sort array by key value

So I have this array.
Array
(
[0] => Array
(
[key_1] => something
[type] => first_type
)
[1] => Array
(
[key_1] => something_else
[type] => first_type
)
[2] => Array
(
[key_1] => something_else_3
[type] => second_type
)
[3] => Array
(
[key_1] => something_else_4
[type] => second_type
)
)
I have to sort by type value in a pattern like this:
first_type
second_type
first_type
second_type
My questions is, how can I do this?
Thanks a lot!
You need to use usort with a custom comparison function that compares the key_1 sub-keys of each item (you can use strcmp to do this conveniently). Assuming you do not want to change the structure of the resulting array, it would look something like this:
$arr = /* your array */
usort($arr, function($a, $b) { return strcmp($a['key_1'], $b['key_1']); });
So here's how I got it to work:
function filter_by_value($array, $index, $value) {
if(is_array($array) && count($array) > 0) {
foreach(array_keys($array) as $key){
$temp[$key] = $array[$key][$index];
if ($temp[$key] == $value){
$newarray[$key] = $array[$key];
}
}
}
return $newarray;
}
$array = /* array here */
$type1 = array_values(filter_by_value($array, 'type', '1'));
$type2 = array_values(filter_by_value($array, 'type', '2'));
$i = 1; $x = 1; $y = 1;
$sorted = array();
foreach ($array as $a) {
if ($i % 2) {
$sorted[$i-1] = $type1[$x-1];
$x++;
} else {
$sorted[$i-1] = $type2[$y-1];
$y++;
}
$i++;
}
Found filter_by_value() on php.net but I don't remember where so, that's not made by me.
Maybe this is not the best solution but it works pretty fine.
If sort() and its relevant alternatives don't work you will have to use usort() or uasort() with a custom function to sort this array.

PHP : flatten array - fastest way? [duplicate]

This question already has answers here:
How to Flatten a Multidimensional Array?
(31 answers)
Closed 5 months ago.
Is there any fast way to flatten an array and select subkeys ('key'&'value' in this case) without running a foreach loop, or is the foreach always the fastest way?
Array
(
[0] => Array
(
[key] => string
[value] => a simple string
[cas] => 0
)
[1] => Array
(
[key] => int
[value] => 99
[cas] => 0
)
[2] => Array
(
[key] => array
[value] => Array
(
[0] => 11
[1] => 12
)
[cas] => 0
)
)
To:
Array
(
[int] => 99
[string] => a simple string
[array] => Array
(
[0] => 11
[1] => 12
)
)
Give this a shot:
$ret = array();
while ($el = each($array)) {
$ret[$el['value']['key']] = $el['value']['value'];
}
call_user_func_array("array_merge", $subarrays) can be used to "flatten" nested arrays.
What you want is something entirely different. You could use array_walk() with a callback instead to extract the data into the desired format. But no, the foreach loop is still faster. There's no array_* method to achieve your structure otherwise.
Hopefully it will help someone else, but here is a function I use to flatten arrays and make nested elements more accessible.
Usage and description here:
https://totaldev.com/flatten-multidimensional-arrays-php/
The function:
// Flatten an array of data with full-path string keys
function flat($array, $separator = '|', $prefix = '', $flattenNumericKeys = false) {
$result = [];
foreach($array as $key => $value) {
$new_key = $prefix . (empty($prefix) ? '' : $separator) . $key;
// Make sure value isn't empty
if(is_array($value)) {
if(empty($value)) $value = null;
else if(count($value) == 1 && isset($value[0]) && is_string($value[0]) && empty(trim($value[0]))) $value = null;
}
$hasStringKeys = is_array($value) && count(array_filter(array_keys($value), 'is_string')) > 0;
if(is_array($value) && ($hasStringKeys || $flattenNumericKeys)) $result = array_merge($result, flat($value, $separator, $new_key, $flattenNumericKeys));
else $result[$new_key] = $value;
}
return $result;
}
This should properly combine arrays with integer keys. If the keys are contiguous and start at zero, they will be dropped. If an integer key doesn't yet exist in the flat array, it will be kept as-is; this should mostly preserve non-contiguous arrays.
function array_flatten(/* ... */)
{
$flat = array();
array_walk_recursive(func_get_args(), function($value, $key)
{
if (array_key_exists($key, $flat))
{
if (is_int($key))
{
$flat[] = $value;
}
}
else
{
$flat[$key] = $value;
}
});
return $flat;
}
You could use !isset($key) or empty($key) instead to favor useful values.
Here's a more concise version:
function array_flatten(/* ... */)
{
$flat = array();
array_walk_recursive(func_get_args(), function($value, $key) use (&$flat)
{
$flat = array_merge($flat, array($key => $value));
});
return $flat;
}

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