php - Sort array of strings by 3rd-to-last character based on another array then sort on whole strings

Solution:

usort

(PHP 4, PHP 5, PHP 7) usort — Sort an array by values using a user-defined comparison function

$unsorted = Array(
"0" =>"3470U11",
"1" =>"3470E11",
"2" =>"3470S13",
"3" =>"3470G11",
"4" =>"3470S12",
"5" =>"3470S11",
"6" =>"3470E12",
"7" =>"3470U12",
"8" =>"3470G13",
"9" =>"3470G12",
"10" => "s3470E13",
"11" => "s3470U13"
);

//$a and $b -> two elts of the array
function cmp ($a,$b){

    $substring_a = substr($a, -3,1);
    $substring_b = substr($b, -3,1);
    
    $sortArr = array('G','D','S','U','E','T','A','L');
    
    $key_a = array_search($substring_a, $sortArr);
    $key_b = array_search($substring_b, $sortArr);
    
    if($key_a == $key_b){
        return strcmp(substr($a, -2),substr($b, -2));
        
    }   
    return $key_a > $key_b;

}

usort($unsorted, "cmp");
print_r($unsorted);
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Solution:

You can use a user defined compare function when sorting. usort() if you want the indexes to be rearanged or uasort() if you want to keep the keys as they are.

Your callback function can be something like this:

public function sortCallback($item1, $item2){
     $orderArr = array('G','D','S','U','E','T','A','L');

     $iItem1 = array_search( substr($item1,-3,1), $orderArr );
     $iItem2 = array_search( substr($item2,-3,1), $orderArr );

     if($iItem1 == $iItem2){
          return 0;
     }

     return ($iItem1 < $iItem2) ? -1 : 1;
}
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See on php.net:

• usort();
• uasort();
• array_search();

Solution:

Try to someting like this....

$unsorted = Array(
        "0" =>"3470U11",
        "1" =>"3470E11",
        "2" =>"3470S13",
        "3" =>"3470G11",
        "4" =>"3470S12",
        "5" =>"3470S11",
        "6" =>"3470E12",
        "7" =>"3470U12",
        "8" =>"3470G13",
        "9" =>"3470G12",
        "10" => "s3470E13",
        "11" => "s3470U13"
    );

    $sortArr = array('G','D','S','U','E','T','A','L');

    foreach ($sortArr as $key => $value) {
        foreach ($unsorted as $key1 => $value1) {
            $val = substr($value1,-3,1);
            if ($val === $value) {
                $sortArrFin[] = $value1;
            }
        }
    }
    foreach ($sortArrFin as $key3 => $value3) {
        $val1 = substr($value3,-2);
        $newSortArr[] = $val1;
    }
    sort($newSortArr);
    $uniqueArr = array_unique($newSortArr);
    foreach ($uniqueArr as $key4 => $value4) {
        foreach ($sortArrFin as $key5 => $value5) {
            $val2 = substr($value5,-2);
            if ($val2 === $value4) {
                $Final[] = $value5;
            }
        }
    }
    foreach ($sortArr as $key6 => $value6) {
        foreach ($Final as $key7 => $value7) {
            $val3 = substr($value7,-3,1);
            if ($val3 === $value6) {
                $Last[] = $value7;
            }
        }
    }
    echo "<pre>";
    print_r($Last);
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Solution:

Assuming:

1. your prioritizing array is an exhaustive list of potential letters and
2. you want to apply a secondary sorting rule which compares whole strings alphabetically and
3. you are running PHP7.4 or higher...

This is a concise, accurate, modern, professional way to implement the required sorting. I am callingusort() which first sorts on the third-last letter based on the original index of the$sortBy array. The "Elvis operator" (?:) separates the first rule from the second rule. The whole string comparision is the fallback sorting rule if the first rule results in a tie.

Code: (Demo)

$unsorted = [
    "3470U11",
    "3470E11",
    "3470S13",
    "3470G11",
    "3470S12",
    "3470S11",
    "3470E12",
    "3470U12",
    "3470G13",
    "3470G12",
    "3470E13",
    "3470U13"
];

$sortBy = ['G', 'D', 'S', 'U', 'E', 'T', 'A', 'L'];
$priority = array_flip($sortBy);

usort(
    $unsorted,
    fn($a, $b) =>
        ($priority[substr($a, -3, 1)] <=> $priority[substr($b, -3, 1)])
        ?: $a <=> $b
);

var_export ($unsorted);
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Output:

array (
  0 => '3470G11',
  1 => '3470G12',
  2 => '3470G13',
  3 => '3470S11',
  4 => '3470S12',
  5 => '3470S13',
  6 => '3470U11',
  7 => '3470U12',
  8 => '3470U13',
  9 => '3470E11',
  10 => '3470E12',
  11 => '3470E13',
)
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Solution:

try this : PHP usort() will the suitable for that

<?php 
   $sortBy_Index = array_flip($sortBy);
   sort($data, SORT_STRING);
   $FlippedData = array_flip($data);
   $compare = function($a, $b) use (&$sortBy_Index, &$FlippedData) {
       $aid = substr($a, -3, 1);$bid = substr($b, -3, 1);
       $ai = $sortBy_Index[$aid];$bi = $sortBy_Index[$bid];

       if ($ai === null and $bi === null) {
          return $FlippedData[$aid] - $FlippedData[$bid];
       }
       if ($ai === null) { return 1; }
       if ($bi === null) { return -1; }

       return $ai - $bi;
  };
  usort($data, $compare);
  echo "<pre>";print_r($data);exit;
?>
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OUTPUT

Array
(
    [0] => 3470G11
    [1] => 3470G12
    [2] => 3470G13
    [3] => 3470S11
    [4] => 3470S12
    [5] => 3470S13
    [6] => 3470U11
    [7] => 3470U12
    [8] => s3470U13
    [9] => 3470E11
    [10] => 3470E12
    [11] => s3470E13
)
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Solution:

try this instead

sort($unsorted);
$result=array();
foreach ($sortArr as $sortBy) {
foreach ($unsorted as $value) {
 if(strpos($value, $sortBy)!==false){
$result[]=$value;
}}}
print_r($result);
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