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phparraysiterationnested-loops

Iterating through multi-dimensional array

I have an array with this structure:

Array ( 
[0] => Array ( [key] => Egg Method [values] => Array ( 
    [0] => Array ( [id] => 1 [value] => Boiled ) 
    [1] => Array ( [id] => 2 [value] => Poached ) 
    [2] => Array ( [id] => 3 [value] => Fried ) 
    [3] => Array ( [id] => 4 [value] => Scrambled ) ) ) 

[1] => Array ( [key] => Bread [values] => Array ( 
    [0] => Array ( [id] => 5 [value] => White ) 
    [1] => Array ( [id] => 6 [value] => Brown ) ) ) 

[2] => Array ( [key] => Egg Hardness [values] => Array ( 
    [0] => Array ( [id] => 7 [value] => Soft ) 
    [1] => Array ( [id] => 7 [value] => Medium )    
    [2] => Array ( [id] => 8 [value] => Hard ) ) ) 

)

How could I iterate through the array to output all of the possible permutations, i.e.

Egg Method: Boiled / Bread: White / Egg Hardness: Soft
Egg Method: Boiled / Bread: White / Egg Hardness: Medium
Egg Method: Boiled / Bread: White / Egg Hardness: Hard
Egg Method: Boiled / Bread: Brown / Egg Hardness: Soft
Egg Method: Boiled / Bread: Brown / Egg Hardness: Medium
Egg Method: Boiled / Bread: Brown / Egg Hardness: Hard
Egg Method: Poached / Bread: White / Egg Hardness: Soft
Egg Method: Poached / Bread: White / Egg Hardness: Medium
Egg Method: Poached / Bread: White / Egg Hardness: Hard
Egg Method: Poached / Bread: Brown / Egg Hardness: Soft
Egg Method: Poached / Bread: Brown / Egg Hardness: Medium
Egg Method: Poached / Bread: Brown / Egg Hardness: Hard
etc etc

One additional problem is I don't know how many criteria arrays there might be, so unfortunately I can't just use 3 nested loops for this.

I am using PHP, although I guess a pseudo code solution will be fine and I can adapt it.

Solution

  • Solved it

    recurse("", $partoptions, 0);

function recurse($longstring, $partoptions, $index) {
    $key = $partoptions[$index]['key'];
    $values = $partoptions[$index]['values'];   
    for ($i=0; $i<sizeof($values); $i++) {                  
        $thisvalue = $values[$i]['value'];  
        if (sizeof($partoptions)>$index+1) {
            $tmplongstring = $longstring . ($longstring==""?"":" / ") . $thisvalue;
            recurse($tmplongstring, $partoptions, $index+1);
        } else {
            echo $longstring . " / " . $thisvalue . "<br>";
        }           
    }
}