Generating Product SKU Combinations Using Cartesian Product in PHP

The author is building an e‑commerce system and needs to batch‑generate product SKUs after adding various specifications such as color, storage, carrier, and region.

SKU generation is achieved by calculating the Cartesian product of the specification arrays, and two PHP approaches are demonstrated.

First method – generate SKU strings:

<?php
function Cartesian($data){
    $len = count($data);
    for($i = 0; $i < $len-1; $i++){
        if($i === 0){
            // first array
            $result = $data[0];
        }
        $temp = [];
        // combine current result with next array
        foreach($result as $res){
            foreach($data[$i+1] as $sec){
                $temp[] = $res . '-' . $sec;
            }
            $result = $temp;
        }
    }
    return $result;
}

// data to compute
$data = array(
    array('白色','银色','玫瑰金'),
    array('64G','128G'),
    array('移动','电信','联通'),
    array('国行','港版')
);

$result = Cartesian($data);
print_r($result);
?>

The function returns a flat array of SKU strings such as "白色-64G-移动-国行".

Second method – generate nested array format:

<?php
function Cartesian($data){
    $len = count($data);
    // take first set
    $result = $data[0];
    for($i = 0; $i < $len-1; $i++){
        $arr1 = $result;
        $result = [];
        foreach($arr1 as $res){
            foreach($data[$i+1] as $sec){
                if(!is_array($res)) $res = array($res);
                if(!is_array($sec)) $sec = array($sec);
                $result[] = array_merge_recursive($res,$sec);
            }
        }
    }
    return $result;
}

$data = array(
    array('白色','银色','玫瑰金'),
    array('64G','128G'),
    array('移动','电信','联通'),
    array('国行','港版')
);

$result = Cartesian($data);
print_r($result);
?>

This version returns a multi‑dimensional array where each SKU component remains in its own sub‑array, as shown by the printed result.