php concat array values into new array php [duplicate] - php

Question

This question already has answers here:
Transpose 2d array, join second level with commas, and join first level with pipes
(5 answers)
Closed 7 months ago.
I have an array with arrays in it representing values in a database.
There are over 100 columns in the db table so the actual count is much higher than this example below of 6 values, the sub-array (Array within the array) index 0-5.
The columns are in each index of the sub-array and the rows are in each index of the main array.
Here is my main array with sub-arrays:
Array
(
[0] => Array
(
[0] => N
[1] => N
[2] => Y
[3] => Y
[4] => Y
[5] => Y
)
[1] => Array
(
[0] => N
[1] => N
[2] => Y
[3] => Y
[4] => N
[5] => Y
)
[2] => Array
(
[0] => N
[1] => N
[2] => Y
[3] => Y
[4] => N
[5] => Y
)
[3] => Array
(
[0] => Y
[1] => Y
[2] => Y
[3] => Y
[4] => Y
[5] => Y
)
What I need to do is concat all the values of each sub index into one array like this:
Array
(
[0] => N,N,N,Y
[1] => N,N,N,Y
[2] => Y,Y,Y,Y
[3] => Y,Y,Y,Y
[4] => Y,N,N,Y
[5] => Y,Y,Y,Y
)
There will always be the same number of columns (sub index) but there will be different amounts of rows (index).

Answer 1

The idea is get the data by column, you're in luck, there's a built in function for that. Its array_column.
So first, get the number of columns and simply use a for loop for that. Then just use implode and assign it inside a new container:
$new = array(); // container
$count = count($arr[0]); // get the number of colums
for ($i = 0; $i < $count; $i++) {
// get the data by column number ($i), then implode and push inside
$new[] = implode(',', array_column($arr, $i));
}
Here's a sample output

Answer 2

Avoid using explicit loops like for and while. Use array_map (it can take the variable mumber of arrays to traverse):
$result = array_map(function (...$column) {
return implode(',', $column);
}, ...$array);
Here is the demo.
By the way, in linear algebra this is called transpose of the matrix.
From PHP7.4 and higher, the same technique can be written as: (Demo)
var_export(
array_map(
fn() => implode(',', func_get_args()),
...$array
)
);
Or: (Demo)
var_export(
array_map(
fn(...$column) => implode(',', $column),
...$array
)
);

Answer 3

I assume that you have defined $column as the total number of column in your db table. Use array_column to get the value according to the column key.
$result = array();
for ($i = 0; $i < $column; $i++) {
$res = array_column($arr, $i);
$result[] = implode(",", $res);
}
For more information about array_column function, check this link.
Oh, just to let you know that array_column function only works for PHP 5.5 and higher.

Answer 4

check if this is what you want
$arr = array(//your array);
$newArr = array(); //data wil lbe saved here
foreach($arr as $arr_one){
$string = "";
foreach($arr_one as $subArr){
$string.=$subArr.",";
}
array_push($newArr,rtrim($string,','));
}
var_dump($newArr);