PHP extract Multidimensional Associative Array Keys as Text

Question

With a basic associative array like:

$ar = array("First" => 1, "Second" , "Third" =>"Three");

if you do:

foreach($ar as $key => $val) {

  var_dump($key);

}

This will produce:

string 'First' (length=5)

int 0

string 'Third' (length=5)

How do you Achieve the same results in a Multidimensional Array?

Something like:

array( 0 => array(
            "First" => 1, "Two", "Third" => "Three"
                )
     );

I tried:

foreach($ar as $k => $v){

        var_dump($ar[0][$k]);
        }

I got:

string 'Two' (length=3)

Instead of:

string 'First' (length=5)

    int 0

    string 'Third' (length=5)

Thanx

Nightmare · Accepted Answer · 2013-12-18 02:59:48Z

3

function get_key(&$arr){
    foreach($arr as $key=>$value){
        if(is_array($value)){
            get_key($value);
        }else{
            var_dump($key);
        }
    }
}
$arr = array(
    'key1'=>array('a'=>1,'b'=>2),
    'key2'=>array('c'=>1,2),
);
get_key($arr);

output:

string(1) "a"
string(1) "b"
string(1) "c"
int(0)

answered Dec 18, 2013 at 2:59

Nightmare

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1 Comment

Universal Grasp Over a year ago

Cool... But Kinda Overkill. Thanx though

Will · Accepted Answer · 2013-12-18 02:53:26Z

2

If $ar is equal to this:

array( 0 => array(
        "First" => 1, "Two", "Third" => "Three"
            )
 );

You could iterate over the inner array to get the same result:

foreach ($ar as $k => $v) {
    foreach ($v as $k2 => $v2) {
            var_dump($k2);
    }
}

Output:

string(5) "First"
  int(0)
string(5) "Third"

answered Dec 18, 2013 at 2:53

Will

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1 Comment

Abby Chau Yu Hoi Over a year ago

no, it is not perfect, if the question is talking about "multi-dimensional", then it can even be a wrong answer. It just catered 2-layer depth. Nightmare's answer is a way more correct one.

Lemon Drop · Accepted Answer · 2013-12-18 02:55:09Z

1

You can iterate through the values of the inner array like this:

foreach($ar[0] as $k => $v){
    var_dump($v);
}

The problem with yours is that you are only looping over 1 element in the ar array, and then applying that number to the array inside of it.

If you also want to do the same thing on both levels, you need another foreach loop like so:

foreach($ar as $k => $v){
    foreach($v as $k => $n){
        var_dump($n);
    }
}

answered Dec 18, 2013 at 2:55

Lemon Drop

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2 Comments

Universal Grasp Over a year ago

Your suggestion Prints even their VALUES... I Want something like: string 'First' (length=5) int 0 string 'Third' (length=5) WITHOUT their VALUES.

Lemon Drop Over a year ago

What do you mean by without thier values? The only other thing you can get from an array is its key and you just change $v to $k in that case.

C. Leung · Accepted Answer · 2013-12-18 03:01:43Z

1

$arr = array(
    0 => array("First" => 1, "Two", "Third" => "Three")
);

foreach ($arr as $key => $value)
{
    foreach ($value as $k => $v)
    {
        var_dump($k);
    }
}

answered Dec 18, 2013 at 3:01

C. Leung

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Comments

StackSlave · Accepted Answer · 2013-12-18 03:07:49Z

1

You can access multidimensional Array keys and indexes like so:

$ary = array('whatever' => array('First' => 1, 'Two', 'Third' => 'Three'),
  array('something' => array('cool' => 'yes', 'awesome' => 'super', 'great' => 10)
);
foreach($ary as $k => $a){
  // $k is each Array key within initial Array
  foreach($a as $i => $v){
    // $i is internal index
    // $v is internal value
  }
}

Note:

In an Array that contains Arrays the first Array is really the value under key 0, unless the Array is assigned to a key, so your key, 0, is not necessary.

edited Dec 18, 2013 at 3:07

answered Dec 18, 2013 at 3:01

StackSlave

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1 Comment

Universal Grasp Over a year ago

Cool... though it can make a Beginner NOSE-BLEED!... llz

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