Sort array of directory path strings by lowest directory (ending substring)

Question

I want to sort this array by year:

Array
(
    [0] => data/pictures/alice/1980
    [1] => data/pictures/alice/1985
    [2] => data/pictures/bob/1981
    [3] => data/pictures/bob/1985
    [4] => data/pictures/bob/1987
    [5] => data/pictures/bob/1989
)

Expected result:

Array
(
    [0] => data/pictures/alice/1980
    [1] => data/pictures/bob/1981
    [2] => data/pictures/alice/1985
    [3] => data/pictures/bob/1985
    [4] => data/pictures/bob/1987
    [5] => data/pictures/bob/1989
)

I've already tried different sort functions without success.

Example:

asort($paths, SORT_STRING | SORT_FLAG_CASE);

sort($path, SORT_NUMERIC);

You want to look at usort().

Rizier123
– Rizier123

2016-10-16 15:36:52 +00:00
Commented Oct 16, 2016 at 15:36 — Rizier123
– Rizier123, Commented Oct 16, 2016 at 15:36

AbraCadaver · Accepted Answer · 2016-10-16 15:56:18Z

5

Since it's a path just map the array through basename() and then sort based on that:

array_multisort(array_map('basename', $paths), SORT_ASC, $paths);

edited Oct 16, 2016 at 15:56

answered Oct 16, 2016 at 15:50

AbraCadaver

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Comments

hummingBird · Accepted Answer · 2016-10-16 15:44:26Z

1

Try this

function cmp($a, $b) {
   // if equal, don't do much
   if ($a == $b) {
       return 0;
   }

   $explodedA = explode('/', $a);
   $explodedB = explode('/', $b);
   $yearPartA = $explodedA[count($explodedA) - 1];
   $yearPartB = $explodedB[count($explodedB) - 1];


   if ($explodedPartA == $explodedPartB) { // compare full string
      return ($a < $b) ? -1 : 1;
   }

   return ($yearPartA < $yearPartB) ? -1 : 1;
}

// actual sort of the array $path (e.g. the whole point)
usort($path, "cmp");

Consider, however that you'd probably be doing 'explode' several times for each array element and that it might be cheaper to work a bit on the array first. Not sure how big your array is... Do some testing.

edited Oct 16, 2016 at 15:44

answered Oct 16, 2016 at 15:41

hummingBird

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3 Comments

Farkie Over a year ago

Show the usort on it :)

OlajosCs Over a year ago

Or he could use substr from the position of the last "/" until the end of the string, but it may not be more efficient than exploding.

hummingBird Over a year ago

true... but i'm actually bothered by the part where elements have to be accessed at least once...

Volker Schukai · Accepted Answer · 2016-10-16 15:50:54Z

0

$array = ['data/pictures/alice/1980','data/pictures/alice/1985','data/pictures/bob/1981','data/pictures/bob/1985','data/pictures/bob/1987','data/pictures/bob/1989'];

uasort($array, function($a,$b) {
    $y1 = array_pop(explode('/', $a));
    $y2 = array_pop(explode('/', $b));
    if($y1===$y2) {
       // if year the same use other criteria
       if($a===$b) {
          return 0;
       }
       return $a>$b?-1:1;
    };
    return $y1>$y2?-1:1;
});

edited Oct 16, 2016 at 15:50

answered Oct 16, 2016 at 15:48

Volker Schukai

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3 Comments

hummingBird Over a year ago

nice touch w/ pop... however,notice the 'problem' when years are the same... i missed it at first, too. for that matter, i think user also missed it when not considering it.

Volker Schukai Over a year ago

the 'problem' when years are the same - what is the problem?

hummingBird Over a year ago

you added the part where it was a problem, why do u ask then? we can all see history

OlajosCs · Accepted Answer · 2016-10-16 15:43:04Z

-1

Use usort and in the custom function explode the strings by "/" and compare the last parts of the arrays.

answered Oct 16, 2016 at 15:43

OlajosCs

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