Dynamically convert keypath values from a flat array into a hierarchical multidimensional array [duplicate]

Question

I have an array like this:

Array(
  'level1' => 'someval',
  'level2' => 'someotherval',
  'level3' => 'thirdval'
)

I want to turn it into this:

Array(
  'someval' => Array(
    'someotherval' => Array(
      'thirdval' => 1
    )
  )
)

Obviously I could build the example above by hand, but I don't know how many levels there will be. And this simple example might seem useless, but there are going to be more values, so there will be multiple arrays inside each of the levels.

Your questions is a little vague? what are you needing to store inside of the multi-dimensional array? What states to which level an array needs to be nested etc etc? Will that pattern continue or do will some levels contain multiple values? — anthony.c
– anthony.c, Commented Nov 3, 2011 at 18:20

genesis · Accepted Answer · 2011-11-03 18:16:24Z

2

This will do it

$array = array(
          'level1' => array(
             'level2' => array(
                 'level3' => 1
              )
           )
         );

answered Nov 3, 2011 at 18:16

genesis

51.1k20 gold badges99 silver badges127 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user774528 Over a year ago

Sorry, I mistyped part of my question. Please also see the last paragraph. I can easily build the array in the manner you demonstrated, but I don't know how many levels there will be, so I need to recursively loop through it or something similar.

jjwdesign Over a year ago

Not sure what you are looking for, but you might research "pass by reference" and "recursive" function/method calls. That might help your understanding some.

Jose · Accepted Answer · 2011-11-03 18:49:25Z

Here's my take on it:

function make_multi_level_array($arr) {
        if (count($arr) == 1) return array(array_pop($arr) => 1);
        else {
                $level_key = array_pop(array_reverse($arr));
                $sub_level = make_multi_level_array(
                        array_slice($arr,1,count($arr)-1)       
                );
                return array(
                        $level_key => $sub_level
                );
        }       

}
$arr = array(
   'level1' => 'someval',
   'level2' => 'someotherval',
   'level3' => 'thirdval',
);

var_dump(make_multi_level_array($arr));

Will output this:

array(1) {
  ["someval"]=>
  array(1) {
    ["someotherval"]=>
    array(1) {
      ["thirdval"]=>
      int(1)
    }
  }
}

Also tried other cases like below.

$arr = array(
  'level1' => 'someval',
  'level2' => 'someotherval',
  'level3' => 'thirdval',
  'level4' => 'fourthval'
);

Seems okay:

array(1) {
  ["someval"]=>
  array(1) {
    ["someotherval"]=>
    array(1) {
      ["thirdval"]=>
      array(1) {
        ["fourthval"]=>
        int(1)
      }
    }
  }
}

user774528 · Accepted Answer · 2011-11-03 19:16:32Z

0

Do you need something like this?

$levels = array_keys(Array(
  'level1' => 'someval',
  'level2' => 'someotherval',
  'level3' => 'thirdval'
));
$array = Array();
$aux = &$array;
foreach ($levels as $level => $value) {
   if ($aux == 1)
       $aux = array($value => 1);
   $aux = &$aux[$value];
}
var_dump($array);

edited Nov 3, 2011 at 19:16

user774528

1873 silver badges12 bronze badges

answered Nov 3, 2011 at 18:31

gustavotkg

4,4392 gold badges22 silver badges29 bronze badges

Collectives™ on Stack Overflow

Dynamically convert keypath values from a flat array into a hierarchical multidimensional array [duplicate]

3 Answers 3

2 Comments

Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Linked

Related