Array of values from and array of arrays without loops - php

Let's say I have a data set in PHP that is in the form of:
$array = [{"prior":"0","id":"61039","type":"todo"},
{"prior":"1","id":"70341","type":"todo"},
{"prior":"3","id":"39104","type":"todo"},
{"prior":"4","id":"70315","type":"todo"},
{"prior":"6","id":"72050","type":"todo"},
{"prior":"7","id":"72329","type":"todo"},
{"prior":"8","id":"73992","type":"todo"}]
I want to process this array of arrays so that I have a single array with integer indexes and the values of only id.
It's trivial to simple use loops:
$data = array();
foreach($array as $item){
$data[] = $item['id'];
}
What I want to know, is there a way to do this, disregarding efficiency, using the built in array functions of PHP (with no loops), or am I stuck using the foreach loop?

You can use array_map() for this:
$data = array_map(function ($el) { return $el['id']; }, $array);
Note that this still has to perform the looping internally; it's just not shown explicitly as in a foreach loop. This approach will be far less efficient than a plain 'ol foreach.
Demo

With PHP >= 5.5.0:
$array = json_decode($array, true);
$ids = array_column($array, 'id');

Related

how to make array like this

I have an array in the array, and I want to make it just one array, and I can easily retrieve that data
i have some like
this
but the coding only combines the last value in the first array, not all values
is it possible to make it like that?
so that I can take arrays easily
I would make use of the unpacking operator ..., combined with array_merge:
$array['test2'] = array_merge(...array_merge(...$array['test2']));
In your case you need to flatten exactly twice, if you try to do it one time too much it will fail due to the items being actual arrays themselves (from PHP's perspective).
Demo: https://3v4l.org/npnTi
Use array_merge (doc) and ... (which break array to separate arrays):
function flatten($arr) {
return array_merge(...$arr);
}
$arr = [[["AAA", "BBB"]], [["CCC"]]];
$arr = flatten(flatten($arr)); // using twice as you have double depth
In your case, $arr is $obj["test2"]. If your object is json cast it to array first and if it is a string use json_decode
Live example: 3v4l
if you have a array then you can use the below code
if(!empty($array['test2'])){
$newarray = array();
foreach ($array['test2'] as $arrayRow) {
$newarray = array_merge($newarray,$arrayRow);
}
$array['test2'] = $newarray;
}

Storing array data in foreach loop in PHP

I am wondering how can I store all values from a foreach loop, I know that I am re-initialising in the loop but I'm not sure how to store the data. Heres my basic loop:
$array = array("v1", "v2", "v3", "v4");
foreach($array as $row){
$arr = array('val' => $row);
echo $row;
}
print_r($arr);
So when I use the print_r($arr) the only thing outputted would be v4 and I know that the values are there because the echo $row; does return each output individually.
My question would be how can I store each instance of row in my array?
Create a new array, fill it:
$array = array("v1", "v2", "v3", "v4");
$newArray = array();
foreach($array as $row){
// notice the brackets
$newArray[] = array('val' => $row);
}
print_r($newArray);
It looks like you are storing your array wrong.
Try adjusting the $arr = array('val' => $row);
to:
$arr[] = array('val' => $row);
This will set it so you pick up each line as a separate array which you can easily navigate through.
Hope this helps!
If I'm reading correctly, you want to transform your array from simple values to key-value pairs of 'val'->number. array_map is a concise way of doing this sort of transformation.
$array = array("v1", "v2", "v3", "v4");
$arr = array_map(function($v) { return array('val'=>$v); }, $array);
print_r($arr);
While it doesn't matter in this case, array_map also has the handy feature of preserving your keys, in case that is desired.
Note that you can also provide a named function to array_map, instead of providing the implementation inline, which can be nice in the event that your transform method gets more complicated. More on array_map here.

PHP array_chunk and then array_merge

is there any way to merge undefined number of arrays? Array_merge doesn't work for me, cause you have to actually put those arrays as parameters, or maybe there is a way.
I've chunked an array into n - number of arrays, I do some stuff on those chunks and would like to merge some other arrays:
$chunky = array_chunk($positions);
$arraytomerge = array();
foreach($chunky as $key=>$val)
{
do some stuff with $keys and $vals
$arraytomerge[] = array('1','2','3','4');
}
$merged = array_merge($arraytomerge[0],$arraytomerge[1]...);
How to list arrays as array_merge parameters?
Instead of doing
//do some stuff with $keys and $vals
$arraytomerge[] = array('1','2','3','4');
Just do
//do some stuff with $keys and $vals
$merged = array_merge($merged,array('1','2','3','4'));
Or better yet, just add your new items directly to the $merged array instead of creating a new array

php turn this array into integer series

this is the output of my array
[["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"]]
but I would like this to look like
[1,1,1,1,1,1,1]
how would this be achieved in php, it seems everything I do gets put into an object in the array, when I don't want that. I tried using array_values and it succeeded in returning the values only, since I did have keys originally, but this is still not the completely desired outcome
$yourArray = [["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"],["1"]];
use following code in PHP 5.3+
$newArray = array_map(function($v) {
return (int)$v[0];
}, $yourArray);
OR use following code in other PHP version
function covertArray($v) {
return (int)$v[0];
}
$newArray = array_map('covertArray', $yourArray)
You could always do a simple loop...
$newArray = array();
// Assuming $myArray contains your multidimensional array
foreach($myArray as $value)
{
$newArray[] = $value[0];
}
You could beef it up a little and avoid bad indexes by doing:
if( isset($value[0]) ) {
$newArray[] = $value[0];
}
Or just use one of the many array functions to get the value such as array_pop(), array_slice(), end(), etc.

Convert array of single-element arrays to a one-dimensional array

I have this kind of an array containing single-element arrays:
$array = [[88868], [88867], [88869], [88870]];
I need to convert this to one dimensional array.
Desired output:
[88868, 88867, 88869, 88870]
Is there any built-in/native PHP functionality for this array conversion?
For your limited use case, this'll do it:
$oneDimensionalArray = array_map('current', $twoDimensionalArray);
This can be more generalized for when the subarrays have many entries to this:
$oneDimensionalArray = call_user_func_array('array_merge', $twoDimensionalArray);
The PHP array_mergeĀ­Docs function can flatten your array:
$flat = call_user_func_array('array_merge', $array);
In case the original array has a higher depth than 2 levels, the SPL in PHP has a RecursiveArrayIterator you can use to flatten it:
$flat = iterator_to_array(new RecursiveIteratorIterator(new RecursiveArrayIterator($array)), 0);
See as well: Turning multidimensional array into one-dimensional array
try:
$new_array = array();
foreach($big_array as $array)
{
foreach($array as $val)
{
array_push($new_array, $val);
}
}
print_r($new_array);
$oneDim = array();
foreach($twoDim as $i) {
$oneDim[] = $i[0];
}
Yup.
$values = array(array(88868), array(88867), array(88869), array(88870));
foreach ($values as &$value) $value = $value[0];
http://codepad.org/f9KjbCCb
foreach($array as $key => $value){
//check that $value is not empty and an array
if (!empty($value) && is_array($value)) {
foreach ($value as $k => $v) {
//pushing data to new array
$newArray[] = $v;
}
}
}
For a two dimensional array this works as well:
array_merge(...$twoDimensionalArray)
While some of the answers on the page that was previously used to close this page did have answers that suited this question (like array_merge(...$array)). There are techniques for this specific question that do not belong on the other page because of the input data structure.
The sample data structure here is an array of single-element, indexed arrays.
var_export(array_column($array, 0));
Is all that this question requires.
If you ever have a daft job interview that asks you to do it without any function calls, you can use a language construct (foreach()) and use "array destructuring" syntax to push values into a result variable without even writing a body for the loop. (Demo)
$result = [];
foreach ($array as [$result[]]);
var_export($result);
Laravel also has a flattening helper method: Arr::flatten()

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