Php, remove key from an array red-handed - php

I want to remove an item from an array. I can write this:
$item = array(
'id' => 1
'name' => 'name'
);
$item2 = $item;
unset($item2['id']);
$names[] = $item2;
but the last 3 lines are somewhat "cumbersome", soo un elegant. Can it be solved without creating $item2 ? Something like:
$item = array(
'id' => 1
'name' => 'name'
);
$names[] = array_ignore_index('id', $item);

From your codes, I can see that you are trying to get the names[] from item array. One possible simple solution for this specific scenario:
For example IF you have :
$items = array(
array(
//this is your item 1
'id' => 1,
'name' => 'name1'
),
array(
//this is item 2
'id' => 2,
'name' => 'name2'
)
);
and you want to retrieve the names in the names array.
You can just do:
$names = array_column($items, 'name');
It will return:
Array
(
[0] => "name1"
[1] => "name2"
)
Please note this solution is best fit for this specific scenario, it may not fit your current scenario depending.

The shortest out of the box solution is to create a diff of the array keys:
$names[] = array_diff_key($item, array_flip(['id']));
See http://php.net/array_diff_key.

function array_ignore_index($id,$item){ ///function
unset($item[$id]);
return $item;
}
$a=array('id'=>1,
'name'=>'name');
$b=array_ignore_index('name',$a);
echo $b['name']; //create error id is not present
Here is the code for required operation..

You can use unset array column
Code is
unset($item['id']);
To test it
print_r($item);

Related

Detect if array of objects within an object has duplicate names

I'm looking for a smart way to find out if my array of objects within an object has multiple name values or not to do a validation since it's only allowed to have one array name per inner array:
$elements = [];
$elements[18][20] = [
[
'name' => 'Color',
'value' => 'Red'
],
[
'name' => 'Color',
'value' => 'Green'
],
[
'name' => 'Size',
'value' => 'S'
]
];
$elements[18][21] = [
[
'name' => 'Size',
'value' => 'S'
],
[
'name' => 'Length',
'value' => '20'
],
];
error_log( print_r( $elements, true ) );
So the object 20 for example is invalid because it has 2 colors with the same value. At the end I was hoping to get a result array containing 1 duplicate name. This way I can output them like: "You have at least one duplicate name: Color".
My first idea was to loop over the array and do a second loop. This way it was possible to receive the inner arrays containing the stuff. Now I was able to add every name to another array. After this I was able to use count() and array_intersect() to receive a value of x which showed me if there are duplicates or not.
Now I had a count, but not the actual value to display. Before I use a semi-good solution, I was hoping to get any ideas here how I can make it better!
This loop will generate your expected output:
foreach($elements[18] as $index => $element){
//Get all the elements' names
$column_key = array_column($element, 'name');
//Get the count of all keys in the array
$counted_values = array_count_values($column_key);
//Check if count is > 1
$filtered_array = array_filter($counted_values, fn($i) => $i > 1);
//If the filter is not empty, show the error
if(!empty($filtered_array)){
//get the key name
$repeated_key = array_key_first($filtered_array);
echo "You have at least one duplicate name: {$repeated_key} at index {$index}";
break;
}
}
It relies in the array_count_values function.

Is there a way to get a named key/value from SUBARRAY without knowing the main key?

Short: Is there a way to get a named key/value from SUBARRAY without knowing the main key ?
Long:
Ive got a foreach loop that extracts text-files & turns them into individual / single arrays (resetting the array between each file)...
example:
Array
(
[Blah Blah] => Array
(
[number] => 10
[name] => nameBlah
[image] =>
)
)
Array
(
[pinkblue597] => Array
(
[number] => 18
[name] => nameBlah68
[image] =>
)
)
(the 1st part to turn into array is used by multiple parts of a process so I dont want to add unnecessary code)
I want to extract the value of "name" and "number", however I do not know the value / format of the key in advance.. - Example: pinkblue597
If I do print_r, I do see the array as I want...
print_r($found,true)."\n";
but if I do this, $name=$found[0]; I get no results for "$name"...
or
if I do this, $name=$found[0]["name"]; I get no results for "$name"...
I could do this via a foreach loop, but it seems inefficient...
PS there will only be ONE (unknown) key in this array, & a sub-array. The sub array is always the same.
Edited: made the code easier to see (forgot to do this)
If the array formation is going to be the same all the time...
then a (nested) foreach loop will suffice, take the example below,
<?php
$a = [
'somethingUnknown13582563' => [
'name' => 'name',
'number' => 15
],
'somethingUnknown2' => [
'name' => 'another name',
'number' => 24
]
];
foreach ($a as $key => $subArray) {
foreach ($subArray as $subKey => $value) {
echo $subArray[$subKey] . '<br>';
}
}
?>
Output
name
15
another name
24
Or...
You could use array_values,
<?php
$a = [
'somethingUnknown13582563' => [
'name' => 'first name',
'number' => 15
],
'somethingUnknown2' => [
'name' => 'name',
'number' => 24
]
];
$a = array_values($a);
echo $a[0]['name'];
?>
Which would turn the first associative array in to numeric indexes and would like so,
array(
0 => array(
'name' => 'first name',
'number' => 15,
),
1 => array(
'name' => 'name',
'number' => 24,
)
)
I'm not sure why you're creating a nested array in the first place if you only intend to discard it immediately, but since the array only appears to have a single element, and you only care about that element, you can simple use array_pop
$a = [
'somethingUnknown13582563' => [
'name' => 'first name',
'number' => 15
],
];
$data = array_pop($a);
echo $data['name']; // gives you 'first name'
Note that array_pop is destructive. So if you don't want this behavior you could use something like end instead.
$data = end($a); // same effect as array_pop but non-destructive
echo $data['name']; // also gives you 'first name'
With that said, the foreach construct isn't necessarily inefficient. I believe your true concern is around finding a simpler way to dereference the nested array. The easiest way to do that in your case is going to be using something like end($a)['name'] which gives you the kind of straight-forward dereferencing you're looking for.
You can use array_map() to achieve this...
array_map — Applies the callback to the elements of the given arrays. This will loop all the array elements through callback function and you can print each element present in the sub array..
<?php
$myArry = array(
'Blah Blah' => array(
'number' => 10,
'name' => 'Blah Blah 1',
),
'pinkblue597' => array(
'number' => 15,
'name' => 'Blah Blah 2',
)
);
array_map(function($arr){
echo 'Name : '.$arr['name'].'<br>';
echo 'Number : '.$arr['number'].'<br>';
},$myArry);
?>
This will give you :
Name : Blah Blah 1
Number : 10
Name : Blah Blah 2
Number : 15

How can I simplify a nested php array?

I'm writing a php web application where I have a nested array which looks similar to the following:
$results = array(
array(
array(
'ID' => 1,
'Name' => 'Hi'
)
),
array(
array(
'ID' => 2,
'Name' => 'Hello'
)
),
array(
array(
'ID' => 3,
'Name' => 'Hey'
)
)
);
Currently this means that when I want to use the ID field I have to call $results[0][0]['ID'] which is rather inefficient and with an array of over several hundred records becomes messy quickly. I would like to shrink the array down so that I can call $results[0]['ID'] instead.
My understanding is that a function that uses a foreach loop to iterate through each row in the array and change the format would be the best way to go about changing the format of the $results array but I am struggling to understand what to do after the foreach loop has each initial array.
Here is the code I have so far:
public function filterArray($results) {
$outputArray = array();
foreach ($results as $key => $row) {
}
return $outputArray;
}
Would anyone be able to suggest the most effective way to achieve what I am after?
Thanks :)
Simply use call_user_func_array as
$array = call_user_func_array('array_merge', $results);
print_r($array);
Demo

Need help about array

What do
$categories[$id] = array('name' => $name, 'children' => array());
and
$categories[$parentId]['children'][] = array('id' => $id, 'name' => $name);
mean?
Thanks a lot.
How should i format the output so i can learn the results that was returned?
You can format your code into tables by looping on the array using for or foreach. Read the docs for each if you don't have a grasp on looping.
2.What does
$categories[$id] = array('name' => $name, 'children' => array());
and
$categories[$parentId]['children'][] = array('id' => $id, 'name' => $name);
The first line assigns an associative array to another element of the $categories array. For instance if you wanted the name of the category with ID of 6 it would look like this:
$categories[6]['name']
The second line does something similar, except when you are working with an array in PHP, you can use the [] operator to automatically add another element to the array with the next available index.
What is the uses of .= ?
This is the concatenation assignment operator. The following two statements are equal:
$string1 .= $string2
$string1 = $string1 . $string2
These all have to do with nesting arrays.
first example:
$categories[$id] = array('name' => $name, 'children' => array());
$categories is an array, and you are setting the key id to contain another array, which contains name and another array. you could accomplish something similar with this:
$categories = array(
$id => array(
'name' => $name,
'children' => array()
)
)
The second one is setting the children array from the first example. when you have arrays inside of arrays, you can use multiple indexes. It is then setting an ID and Name in that array. here is a another way to look at example #2:
$categories = array(
$parentID => array(
'children' => array(
'id' = $id,
'name' => $name
)
)
)
note: my two ways of rewriting are functionally identical to what you posted, I'm just hoping this makes it easier to visualize what's going on.

Retrieve first key in multi-dimensional array using PHP

I would like to retrieve the first key from this multi-dimensional array.
Array
(
[User] => Array
(
[id] => 2
[firstname] => first
[lastname] => last
[phone] => 123-1456
[email] =>
[website] =>
[group_id] => 1
[company_id] => 1
)
)
This array is stored in $this->data.
Right now I am using key($this->data) which retrieves 'User' as it should but this doesn't feel like the correct way to reach the result.
Are there any other ways to retrieve this result?
Thanks
There are other ways of doing it but nothing as quick and as short as using key(). Every other usage is for getting all keys. For example, all of these will return the first key in an array:
$keys=array_keys($this->data);
echo $keys[0]; //prints first key
foreach ($this->data as $key => $value)
{
echo $key;
break;
}
As you can see both are sloppy.
If you want a oneliner, but you want to protect yourself from accidentally getting the wrong key if the iterator is not on the first element, try this:
reset($this->data);
reset():
reset() rewinds array 's internal
pointer to the first element and
returns the value of the first array
element.
But what you're doing looks fine to me. There is a function that does exactly what you want in one line; what else could you want?
Use this (PHP 5.5+):
echo reset(array_column($this->data, 'id'));
I had a similar problem to solve and was pleased to find this post. However, the solutions provided only works for 2 levels and do not work for a multi-dimensional array with any number of levels. I needed a solution that could work for an array with any dimension and could find the first keys of each level.
After a bit of work I found a solution that may be useful to someone else and therefore I included my solution as part of this post.
Here is a sample start array:
$myArray = array(
'referrer' => array(
'week' => array(
'201901' => array(
'Internal' => array(
'page' => array(
'number' => 201,
'visits' => 5
)
),
'External' => array(
'page' => array(
'number' => 121,
'visits' => 1
)
),
),
'201902' => array(
'Social' => array(
'page' => array(
'number' => 921,
'visits' => 100
)
),
'External' => array(
'page' => array(
'number' => 88,
'visits' => 4
)
),
)
)
)
);
As this function needs to display all the fist keys whatever the dimension of the array, this suggested a recursive function and my function looks like this:
function getFirstKeys($arr){
$keys = '';
reset($arr);
$key = key($arr);
$arr1 = $arr[$key];
if (is_array($arr1)){
$keys .= $key . '|'. getFirstKeys($arr1);
} else {
$keys = $key;
}
return $keys;
}
When the function is called using the code:
$xx = getFirstKeys($myArray);
echo '<h4>Get First Keys</h4>';
echo '<li>The keys are: '.$xx.'</li>';
the output is:
Get First Keys
The keys are: referrer|week|201901|Internal|page|number
I hope this saves someone a bit of time should they encounter a similar problem.

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