I want to print all unique Department values from a multidimensional array as a comma-separated string, but not all rows have a Department value.
The boiled down version of my array looks like this:
$employee = [
["employee_id" => 1, "Department" => "Tech"],
["employee_id" => 2, "Department" => "Tech"],
["employee_id" => 3],
["employee_id" => 4, "Department" => "Tech"],
["employee_id" => 5],
["employee_id" => 6, "Department" => "Crm"],
["employee_id" => 7],
["employee_id" => 8, "Department" => "Crm"],
["employee_id" => 9, "Department" => "Crm"],
["employee_id" => 10],
["employee_id" => 11, "Department" => "Crm"],
["employee_id" => 12, "Department" => "Crm"]
];
I tried with:
for ($i=0; $i < count($employee); $i++) {
print_r(array_unique($employee[$i]['Department']));
}
But I generate Warnings when I try to access a non-existent Department value.
Expected output:
Tech,Crm
<?php
echo implode(",",array_unique(array_column($employee,'Department')));
Use array_column to filter values of Department column and use array_unique() to have unique values of Department. Now, just implode() them based on ,.
You can avoid calling array_unique() after array_column() by repeating its second parameter as its third parameter. PHP does no allow duplicate kays on the same level as an array. When a repeated Department is encountered, the old value is replaced with its newer, identical value.
Code: (Demo)
echo implode(',', array_column($employee, 'Department', 'Department'));
// Tech,Crm
Related
Hello here is an array of all values possibilities that should be an instance of the int we have as rank. But I would like this array to be empty first and find those values without if statements, so with a smart mathematical relation.
Example: a player who has the rank 3 would have those rewards: First time: At pos 0: 10 keys; pos 1: 13 keys; pos 2: 13 keys; 8 lives and 2 keys at pos 0 if he already registered their first time rewards.
(In fact there would be if satement only if the player never registered their rewards).
So I've tried to do this with digital sequences that I learned to school but it does not seems working.
Thank you for your time... and your help !
P.S.: I'm quite new here, sorry for any mistake.
Here is the schema of all possibilities stored in this array:
$rewards = [
1 => [
"count" => [7, 7, 7],
"lives" => 8,
"count_back" => [2, 2]
],
2 => [
"count" => [7, 10, 10],
"lives" => 10,
"count_back" => [1]
],
3 => [
"count" => [10, 13, 13],
"lives" => 13,
"count_back" => [2]
],
4 => [
"count" => [10, 13, 13],
"lives" => 15,
"count_back" => [2]
],
5 => [
"count" => [14, 15, 15],
"lives" => 18,
"count_back" => [2]
],
6 => [
"count" => [16, 18, 18],
"lives" => 20,
"count_back" => [2, 2]
]
];
So the only input we have for this command is the player rank (int). Starting to it I would like to find without if statements, that will be too big or this complete array we have above that would take too much datas in memory for nothing (because the player doesn't have several ranks) ; the specific reward.
For example: I have the input 1. So the output should be ["count" => [7, 7, 7], "lives" => 8] if the player never used the command. If he already used it so the output should be only ["count" => [2, 2]]
Application to Distribute Stock between Warehouses
I have two arrays,
One has list of Warehouses along with the Current Quantity: (This can be Dynamic with one or more locations)
[
['location_name' => 'Toronto', 'current_qty' => 3],
['location_name' => 'Mississauga','current_qty' => 7],
['location_name' => 'London', 'current_qty' => 5],
]
The Other array has the Amount of Stock that would be Comming in:
[
'qty' => 5
]
And want to distribute the Qty among the locations so that the current qty of each of the locations would be near equal to each other. So want to return an array with the number that needs to be added to each location. Like: Here , of the 5, 3 went to Toronto and 2 to London. So it can be seen then after the nearest equalization, rest of the distribution can be done randomly.
[
['location_name' => 'Toronto', 'add_qty' => 3],
['location_name' => 'Mississauga','add_qty' => 0],
['location_name' => 'London', 'add_qty' => 2],
]
And Just cannot figure out the logic of this algorithm. Would really appreciate any pointers. Many Thanks.
I would do it like this, not really sure about any performance issues. I don't know how big your data set is.
$locations = [
['location_name' => 'Toronto', 'current_qty' => 3, 'add_qty' => 0],
['location_name' => 'Mississauga', 'current_qty' => 7, 'add_qty' => 0],
['location_name' => 'London', 'current_qty' => 5, 'add_qty' => 0],
];
$supplies = 5;
// This function sorts locations, by comparing the sum of the current quantity and the quantity the location will get.
$locationsByQuantityAscending = function ($locationA, $locationB) {
return ($locationA['current_qty'] + $locationA['add_qty']) - ($locationB['current_qty'] + $locationB['add_qty']);
};
// Sort the locations, getting the ones with the lowest quantity first.
usort($locations, $locationsByQuantityAscending);
// Keep dividing, until we're out of supplies
while ($supplies > 0) {
$locations[0]['add_qty']++; // Add one to the location with the lowest supplies
$supplies--; // Decrease the supplies by one
usort($locations, $locationsByQuantityAscending); // Sort the locations again.
}
print_r($locations);
At the end, this will output:
Array
(
[0] => Array
(
[location_name] => Toronto
[current_qty] => 3
[add_qty] => 3
)
[1] => Array
(
[location_name] => London
[current_qty] => 5
[add_qty] => 2
)
[2] => Array
(
[location_name] => Mississauga
[current_qty] => 7
[add_qty] => 0
)
)
If you really need to be performant, you could also just sort the locations once by their current quantity. Then keep adding to the first location, until its stock will be higher than the second location. Then, until the quantity at the second location is higher than the third location, add one to the first and second location, etc.
I think this will be more performant, since you don't have to sort all your locations X times (X being the number of supplies to divide). I'll leave that implementation to you.
Hint: have a look at recursive functions
If performance is critical, and the input data is usually bigger then shown here (e.g. a lot more locations or a lot more quantity to distribute). You might want to consider using SplMinHeap:
For example:
<?php
$helper = new class extends SplMinHeap
{
public function compare($a, $b): int
{
return ($b['current_qty'] + $b['add_qty']) <=> ($a['current_qty'] + $a['add_qty']);
}
};
$locations = [
['location_name' => 'Toronto', 'current_qty' => 3, 'add_qty' => 0],
['location_name' => 'Mississauga', 'current_qty' => 7, 'add_qty' => 0],
['location_name' => 'London', 'current_qty' => 5, 'add_qty' => 0],
];
foreach ($locations as $entry) {
$helper->insert($entry);
}
$qty = 10000;
while ($qty-- > 0) {
$min = $helper->extract();
$min['add_qty']++;
$helper->insert($min);
}
print_r(iterator_to_array($helper));
https://3v4l.org/nDOY8
I am writing a script that loops through a multidimensional array and it's working as hoped (sort of) but I get errors that I just can't remedy.
I am still not that comfortable building loops to manage nested arrays.
Here is my code. The goal is to sort each layer by the value of the sequence key and in the end I export the array as json.
The sequence key may or may not exist in every sub array so that may need some sort of if clause
<?php
$list = [
"key" => "book",
"sequence" => 1,
"items" => [
[
"key" => "verse",
"sequence" => 2,
"items" => [
["sequence" => 3],
["sequence" => 1],
["sequence" => 2],
],
],
[
"key" => "page",
"sequence" => 1,
"items" => [
[
"key" => "page",
"sequence" => 2,
"items" => [
["sequence" => 2],
["sequence" => 1],
["sequence" => 3],
],
],
[
"key" => "paragraph",
"sequence" => 1,
"items" => [
["sequence" => 2],
["sequence" => 1],
["sequence" => 3],
],
],
],
],
],
];
function sortit(&$array){
foreach($array as $key => &$value){
//If $value is an array.
if(is_array($value)){
if($key == "items"){
uasort($value, function($a,&$b) {
return $a["sequence"] <=> $b["sequence"];
});
}
//We need to loop through it.
sortit($value);
} else{
//It is not an array, so print it out.
echo $key . " : " . $value . "<br/>";
}
}
}
sortit($list);
echo "<pre>";
print_r($list);
?>
Here is the output and error I am getting, and I think I understand why the error is being thrown but at the same time I can not implement the proper checks needed to fix the error.
key : book
sequence : 1
key : page
sequence : 1
E_WARNING : type 2 -- Illegal string offset 'sequence' -- at line 39
E_NOTICE : type 8 -- Undefined index: sequence -- at line 39
sequence : 1
sequence : 2
sequence : 3
sequence : 1
key : page
E_WARNING : type 2 -- Illegal string offset 'sequence' -- at line 39
E_NOTICE : type 8 -- Undefined index: sequence -- at line 39
sequence : 1
sequence : 2
sequence : 3
sequence : 2
key : verse
Not that I am worried to much but another thing that I would like is the array to still be structured in the original order, ie: key, sequence, items
Using usort and array references makes it straightforward. If we're dealing with an array with a set item key, sort the item array and recurse on its children, otherwise, we're at a leaf node and can return.
function seqSort(&$arr) {
if (is_array($arr) && array_key_exists("items", $arr)) {
usort($arr["items"], function ($a, $b) {
return $a["sequence"] - $b["sequence"];
});
foreach ($arr["items"] as &$item) {
$item = seqSort($item);
}
}
return $arr;
}
Result:
array (
'key' => 'book',
'sequence' => 1,
'items' =>
array (
0 =>
array (
'key' => 'page',
'sequence' => 1,
'items' =>
array (
0 =>
array (
'key' => 'page',
'sequence' => 1,
'items' =>
array (
0 =>
array (
'sequence' => 1,
),
1 =>
array (
'sequence' => 2,
),
2 =>
array (
'sequence' => 3,
),
),
),
),
),
1 =>
array (
'key' => 'verse',
'sequence' => 2,
'items' =>
array (
0 =>
array (
'sequence' => 1,
),
1 =>
array (
'sequence' => 2,
),
2 =>
array (
'sequence' => 3,
),
),
),
),
)
Try it!
Note that the outermost structure is a root node that isn't part of an array and can't be sorted (this may be unintentional and causing confusion).
I want to select 5 random ID's from my array of rows. Here is my array $test:
$test = [
['id' => 13, 'pets' => 8],
['id' => 15, 'pets' => 8],
['id' => 16, 'pets' => 10],
['id' => 17, 'pets' => 9],
['id' => 18, 'pets' => 10],
['id' => 19, 'pets' => 10],
['id' => 20, 'pets' => 0],
['id' => 21, 'pets' => 8],
['id' => 22, 'pets' => 9],
['id' => 23, 'pets' => 4],
['id' => 24, 'pets' => 0],
['id' => 40, 'pets' => 8],
['id' => 43, 'pets' => 2],
];
How can I select 5 random ID's from the array and put them into a string like this:
$ids = '13,17,18,21,43';
I've tried to use array_rand(), but it does not seem to work for my type of array. I'm not sure if there are any other built in PHP functions that can do this type of job or if I have to create my own function. It would be nice to have my own function like this to plug in the number of required values.
You can use array_column to only get the ID's and shuffle them.
Then use array_slice to get five items and implode.
$id = array_column($arr, "id");
Shuffle($id);
Echo implode(",", array_slice($id, 0, 5));
First extract the id column indexing also by the id, then pick 5 random ones, and finally implode into a comma separated list. Since keys must be unique, this has the added benefit of not returning duplicate ids if there happen to be duplicates in the array:
$ids = implode(',', array_rand(array_column($test, 'id', 'id'), 5));
For a function:
function array_rand_multi($array, $key, $num) {
return implode(',', array_rand(array_column($array, $key, $key), $num));
}
If you want random, unique ids in a random order, I recommend shuffling the array, then isolating upto 5 subarrays, then extracting the id values, then joining with commas. This way array_column() doesn't need to iterate the full array.
Code: (Demo)
shuffle($test);
echo implode(
',',
array_column(
array_slice($test, -5),
'id'
)
);
If you want random, unique ids and don't mind that they will be in the same order as your input rows, then array_rand() can be used.
#AbraCadaver's approach works by applying temporary keys to the input array, picking five random keys, then joining with commas. Because the values inside the rows are never used, null can also be used as array_column()'s second parameter. These approaches should not be used if duplicate ids need to be honored. In other words, because id values are being applied to the first level keys, php will automatically destroy any rows with duplicated ids -- because a single level of an array cannot contain duplicate keys.
One way to avoid potentially destroying data is to call array_rand() on the original indexes of the input array, then filter those unique indexes by 5 randomly selected indexes. (Demo)
echo implode(
',',
array_column(
array_intersect_key(
$test,
array_flip(array_rand($test, 5))
),
'id'
)
);
Finally, if you want 5 randomly selected, randomly ordered ids which may be selected more than once, then just make 5 iterated calls of array_rand(). (Demo)
for ($x = 0, $delim = ''; $x < 5; ++$x, $delim = ',') {
echo $delim . $test[array_rand($test)]['id'];
}
Or (Demo)
echo implode(
',',
array_map(
fn() => $test[array_rand($test)]['id'],
range(1, 5)
)
);
You can proceed like this (short example) :
<?php
$items = array(
array("id" => 43, "pets" =>2),
array("id" => 40, "pets" =>8),
array("id" => 24, "pets" =>0),
array("id" => 23, "pets" =>4),
);
$ids = $items[array_rand($items)]["id"].",".$items[array_rand($items)]["id"].",".$items[array_rand($items)]["id"];
echo $ids;
// Output Example : 24, 40, 23
?>
It will choose a random key from the main array ($items), example : 3, and output the "id" :
$items[3]["id"]
for this example.
Here is a demo : http://sandbox.onlinephpfunctions.com/code/32787091e341cdf8e172d96b065b14b3ca834846
I've stumbled upon this function today:
public function rules()
{
return [
['status', 'default', 'value' => self::STATUS_ACTIVE],
['status', 'in', 'range' => [self::STATUS_ACTIVE, self::STATUS_DELETED]],
];
}
I don't understand this construction:
['status', 'default', 'value' => self::STATUS_ACTIVE]
How's that first two entries have only value, and the third has a key and a value. Is it something that PHP language allows?
This is nothing new. Key is just optional. You can find a similar case in the very first example of the PHP documentation for arrays.
Here it is.
<?php
$fruits = array (
"fruits" => array("a" => "orange", "b" => "banana", "c" => "apple"),
"numbers" => array(1, 2, 3, 4, 5, 6),
"holes" => array("first", 5 => "second", "third")
);
?>
http://php.net/manual/en/function.array.php