Question

How to create a common sorted unique array from 3 integer arrays in PHP

Answer 1

/* 
   Function: mergeArrays
   Purpose:  Combine three integer arrays into a single array.
*/
function mergeArrays(array $arrA, array $arrB, array $arrC): array {
    $arrMerged = [];

    // Append all elements
    $arrMerged = array_merge($arrA, $arrB, $arrC);

    return $arrMerged;
}

/* 
   Function: uniqueSorted
   Purpose:  Convert an array into a sorted array with unique elements.
             Uses array_unique to remove duplicates, then sorts the result.
*/
function uniqueSorted(array $arr): array {
    $arrUnique = array_unique($arr);   // remove duplicates
    
    sort($arrUnique);                  // sort ascending
    
    return $arrUnique;
}

// Input arrays 
$arr1 = [5, 1, 14, 3, 8, 9, 1, 1, 7];
$arr2 = [3, 5, 7, 2, 3];
$arr3 = [2, 9, 8];

// Step 1: Merge all arrays 
$arrMerged = mergeArrays($arr1, $arr2, $arr3);

// Step 2: Create sorted unique array 
$arrResult = uniqueSorted($arrMerged);

// Step 3: Print result 
echo "Sorted unique array: ";
foreach ($arrResult as $x) {
    echo $x . " ";
}


/* 
run:

Sorted unique array: 1 2 3 5 7 8 9 14 

*/

 

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