CODEWITHSUNDEEP
php
Marty Wallace
Marty Wallace

Reputation: 35754

PHP - get specific element form each sub array without looping

In php is there a way to get an element from each sub array without having to loop - thinking in terms of efficiency.

Say the following array:

$array = array(
    array(
        'element1' => a,
        'element2' => b
    ),
    array(
        'element1' => c,
        'element2' => d
    )
);

I would like all of the 'element1' values from $array

Upvotes: 4

Views: 1691

Answers (4)

Narek
Narek

Reputation: 3823

Without loop? Recursion!

$array = array(
        array(
                'element1' => 'a',
                'element2' => 'b'
        ),
        array(
                'element1' => 'c',
                'element2' => 'd'
        )
);

function getKey($array,$key,$new = array()){
    $count = count($array); 
    $new[] = $array[0][$key];
    array_shift($array);

    if($count==1)
        return $new;

    return getKey($array,$key,$new);
}

print_R(getKey($array,'element1'));

As I understood from Wikipedia Recursion is not a loop.

Upvotes: 0

Mark Baker
Mark Baker

Reputation: 212452

If you're running PHP 5.5 (currently the beta-4 is available), then the following

$element1List = array_column($array, 'element1');

should give $element1List as an simple array of just the element1 values for each element in $array

$array = array(
    array(
       'element1' => a,
       'element2' => b
   ),
   array(
       'element1' => c,
       'element2' => d
   )
);

$element1List = array_column($array, 'element1');
print_r($element1List);

gives

Array
(
    [0] => a
    [1] => c
)

Upvotes: 2

Ashwini Agarwal
Ashwini Agarwal

Reputation: 4858

You can use array_map.

Try code below...

$arr = $array = array(
    array(
       'element1' => a,
       'element2' => b
   ),
   array(
       'element1' => c,
       'element2' => d
   )
);

print_r(array_map("getFunc", $arr));

function getFunc($a) 
{ 
    return $a['element1']; 
}

See Codepad.

But I think array_map will also use loop internally.

Upvotes: 2

Phill Sparks
Phill Sparks

Reputation: 20909

There are a number of different functions that can operate on arrays for you, depending on the output desired...

$array = array(
    array(
       'element1' => 'a',
       'element2' => 'b'
   ),
   array(
       'element1' => 'c',
       'element2' => 'd'
   )
);

// array of element1s : array('a', 'c')
$element1a = array_map(function($item) { return $item['element1']; }, $array);

// string of element1s : 'ac'
$element1s = array_reduce($array, function($value, $item) { return $value . $item['element1']; }, '');

// echo element1s : echo 'ac'
array_walk($array, function($item) {
    echo $item['element1'];
});

// alter array : $array becomes array('a', 'c')
array_walk($array, function(&$item) {
    $item = $item['element1'];
});

Useful documentation links:

Upvotes: 4

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