按日期排序PHP数组

Question

I have a bunch of files that are in an array

im(month)(day)(year)

im01012007

im01022006

im01022012

im01032011

im01042010

im01042012

im01052009

im01052011

im01062012

im01072008

im01072011

etc..

is there a way to sort the array so that it sorted by year then month then day?

Answer 1

You can try use usort

$string = "im01012007.jpg,im01022006.jpg,im01022012.jpg,im01032011.jpg,im01042010.jpg,im01042012.jpg,im01052009.jpg,im01052011.jpg,im01062012.jpg,im01072008.jpg,im01072011.jpg";
$array = explode(",", $string); // rebulding your array ;

var_dump($array);

usort($array, function ($a, $b) {
    $a = DateTime::createFromFormat("mdY", substr(pathinfo($a, PATHINFO_FILENAME), 2));
    $b = DateTime::createFromFormat("mdY", substr(pathinfo($b, PATHINFO_FILENAME), 2));
    return ($a == $b) ? 0 : (($a < $b) ? - 1 : 1);
});

var_dump($array);

Output

Before

array
  0 => string 'im01012007.jpg' (length=14)
  1 => string 'im01022006.jpg' (length=14)
  2 => string 'im01022012.jpg' (length=14)
  3 => string 'im01032011.jpg' (length=14)
  4 => string 'im01042010.jpg' (length=14)
  5 => string 'im01042012.jpg' (length=14)
  6 => string 'im01052009.jpg' (length=14)
  7 => string 'im01052011.jpg' (length=14)
  8 => string 'im01062012.jpg' (length=14)
  9 => string 'im01072008.jpg' (length=14)
  10 => string 'im01072011.jpg' (length=14)

After

array
  0 => string 'im01022006.jpg' (length=14)
  1 => string 'im01012007.jpg' (length=14)
  2 => string 'im01072008.jpg' (length=14)
  3 => string 'im01052009.jpg' (length=14)
  4 => string 'im01042010.jpg' (length=14)
  5 => string 'im01032011.jpg' (length=14)
  6 => string 'im01052011.jpg' (length=14)
  7 => string 'im01072011.jpg' (length=14)
  8 => string 'im01022012.jpg' (length=14)
  9 => string 'im01042012.jpg' (length=14)
  10 => string 'im01062012.jpg' (length=14)