Recursively cycle every path of an array

Question

I have the following(json) object:

$obj = json_decode(\'{
    \"Group1\": {
        \"Blue\": {
            \"Round\": [
                \"Harold\",
                 


        

Answer 1

I've boiled down my method to something VERY simple and easy to read. See inline comments for explanations. I have two versions: a 4-line echoing function and an array returning function.

*Note this method is very SPECIFICALLY built for this question because:

• The input array will ALWAYS have a depth of at least two levels AND

Method #1 - echo strings from inside the function: (Demo)

$array=json_decode('{
    "Group1": {
        "Blue": {
            "Round": {
                "One": [
                    "Lawrence",
                    "Anant",
                    "B."
                ],
                "Two": [
                    "Erwin"
                ]
            }
        },
        "Green": [
           "Bryan",
           "Mick"
        ]
    },
    "Group2": [
        "Peter",
        "Kris"
    ]
}', true);

function recurse($array,$path=''){
    foreach($array as $k=>$v){
        if(!is_array(current($v))){  // check type of the first sub-element's value
            echo ($path?"$path > ":''),"$k > (".implode(', ',$v).")\n";  // don't recurse, just implode the indexed elements
        }else{                                                           // recurse because at least 2 levels below
            recurse($v,($path?"$path > $k":$k));                         // build path appropriately
        }
    }
}
recurse($array);

Output:

Group1 > Blue > Round > One > (Lawrence, Anant, B.)
Group1 > Blue > Round > Two > (Erwin)
Group1 > Green > (Bryan, Mick)
Group2 > (Peter, Kris)

---

Method #2 - return a 4-element array of paths: (Demo)

function recurse($array,$path='',&$result=[]){
    foreach($array as $k=>$v){
        if(!is_array(current($v))){  // check type of the first sub-element's value
            $result[]=($path?"$path > ":'')."$k > (".implode(', ',$v).')';  // don't recurse, just implode the indexed elements
        }else{  // recurse because at least 2 levels below
            recurse($v,($path?"$path > ":'').$k,$result);  // build path appropriately
        }
    }
    return $result;
}
var_export(recurse($array));

Output:

array (
  0 => 'Group1 > Blue > Round > One > (Lawrence, Anant, B.)',
  1 => 'Group1 > Blue > Round > Two > (Erwin)',
  2 => 'Group1 > Green > (Bryan, Mick)',
  3 => 'Group2 > (Peter, Kris)',
)

---

And one final update:

The best advice I can give would be to cut out this middle step and just convert your raw/initial json string to your new desired output (no recursion/stacking required):

Code: (Demo)

$seperateArray = json_decode('[
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "One", "tier5": "Lawrence" },
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "One", "tier5": "Anant" },
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "One", "tier5": "B." },
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Two", "tier5": "Erwin" },
{ "tier1": "Group1", "tier2": "Green", "tier3": "Bryan" },
{ "tier1": "Group1", "tier2": "Green", "tier3": "Mick" },
{ "tier1": "Group2", "tier2": "Peter" },
{ "tier1": "Group2", "tier2": "Kris" }]',true);

foreach($seperateArray as $row){
    $last_val=current(array_splice($row,-1));  // extract last element, store as string
    $results[implode(' > ',$row)][]=$last_val;
}
foreach($results as $k=>$v){
    echo "$k > (",implode(', ',$v),")\n";
}
// same output as earlier methods