PHP group certain results from foreach on array into another array - php

Question

I have an array that looks something like this:
$array = array( [0] => FILE-F01-E1-S01.pdf
[1] => FILE-F01-E1-S02.pdf
[2] => FILE-F01-E1-S03.pdf
[3] => FILE-F01-E1-S04.pdf
[4] => FILE-F01-E1-S05.pdf
[5] => FILE-F02-E1-S01.pdf
[6] => FILE-F02-E1-S02.pdf
[7] => FILE-F02-E1-S03.pdf );
Basically, I need to look at the first file and then get all the other files that have the same beginning ('FILE-F01-E1', for example) and put them into an array. I don't need to do anything with the other ones at this point.
I've been trying to use a foreach loop finding the previous value to do this, but am not having any luck.
Like this:
$previousFile = null;
foreach($array as $file)
{
if(substr_replace($previousFile, "", -8) == substr_replace($file, "", -8))
{
$secondArray[] = $file;
}
$previousFile = $file;
}
So then $secondArray would look like this:
Array ( [0] => FILE-F01-E1-S01.pdf [1] => FILE-F01-E1-S02.pdf
[2] => FILE-F01-E1-S03.pdf [3] => FILE-F01-E1-S04.pdf
[4] => FILE-F01-E1-S05.pdf)
As my result.
Thank you!

Answer 1

You can use array_filter combined with strpos:
$result = array_filter($array, function($filename) {
return strpos($filename, 'FILE-F01-E1') === 0;
});

Answer 2

Are you sure this will be the naming format? That is crucial information to have to construct a regexp or something to check for being a substring of the following strings.
If we can assume this and that the "base" name is always at index 0 then you could do something like.
<?php
$myArr = [
'FILE-F01-E1-S01.pdf',
'FILE-F01-E1-S02.pdf',
'FILE-F01-E1-S03.pdf',
'FILE-F01-E1-S04.pdf',
'FILE-F01-E1-S05.pdf',
'FILE-F02-E1-S01.pdf',
'FILE-F02-E1-S02.pdf',
'FILE-F02-E1-S03.pdf'
];
$baseName = '';
$allSimilarNames = [];
foreach($myArr as $index => &$name) {
if($index == 0) {
$baseName = substr($name, 0, strrpos($name, '-'));
$allSimilarNames[] = $name;
}
else {
if(strpos($name, $baseName) === 0) {
$allSimilarNames[] = $name;
}
}
}
var_dump($allSimilarNames);
This will
Check at index one to get the base name to compare against
Loop all items in the array and match all items, no matter where in the array they are, that are similar according to your naming convention
So if you next time have an array that is
$myArr = [
'FILE-F02-E1-S01.pdf',
'FILE-F01-E1-S01.pdf',
'FILE-F01-E1-S02.pdf',
'FILE-F01-E1-S03.pdf',
'FILE-F01-E1-S04.pdf',
'FILE-F01-E1-S05.pdf',
'FILE-F02-E1-S02.pdf',
'FILE-F02-E1-S03.pdf'
];
this will return all the items that match FILE-F02-E1*.
You could also make a small function of it for easier use and not have to rely on the element at index 0 having to be the "base" name.
<?php
function findMatches($baseName, &$names) {
$matches = [];
$baseName = substr($baseName, 0, strrpos($baseName, '-'));
foreach($names as &$name) {
if(strpos($name, $baseName) === 0) {
$matches[] = $name;
}
}
return $matches;
}
$myArr = [
'FILE-F01-E1-S01.pdf',
'FILE-F01-E1-S02.pdf',
'FILE-F01-E1-S03.pdf',
'FILE-F01-E1-S04.pdf',
'FILE-F01-E1-S05.pdf',
'FILE-F02-E1-S01.pdf',
'FILE-F02-E1-S02.pdf',
'FILE-F02-E1-S03.pdf'
];
$allSimilarNames = findMatches('FILE-F01-E1-S01.pdf', $myArr);
var_dump($allSimilarNames);

Answer 3

Run a simple foreach with strpos() which looks for an occurrence of a string within a string.
$results = array();
foreach($array as $item){
if (strpos($item, 'FILE-F01-E1') === 0) {
array_push($results, $item);
}
}

Answer 4

You could get the first item from the array and use explode and implode to get the part from the filename without the last hyphen and the content after that.
Then use array_filter and use substr using 0 as the start position and the length of the $fileBeginning as the length to check if the string starts with FILE-F01-E1:
$array = [
'FILE-F01-E1-S01.pdf',
'FILE-F01-E1-S02.pdf',
'FILE-F01-E1-S03.pdf',
'FILE-F01-E1-S04.pdf',
'FILE-F01-E1-S05.pdf',
'FILE-F02-E1-S01.pdf',
'FILE-F02-E1-S02.pdf',
'FILE-F02-E1-S03.pdf',
"TESTFILE-F01-E1-S03.pdf"
];
$parts = explode('-', $array[0]);
array_pop($parts);
$fileBeginning = implode('-', $parts);
$secondArray = array_filter($array, function ($x) use ($fileBeginning) {
return substr($x, 0, strlen($fileBeginning)) === $fileBeginning;
});
print_r($secondArray);
Result
Array
(
[0] => FILE-F01-E1-S01.pdf
[1] => FILE-F01-E1-S02.pdf
[2] => FILE-F01-E1-S03.pdf
[3] => FILE-F01-E1-S04.pdf
[4] => FILE-F01-E1-S05.pdf
)
Demo