How can I unset an array's children values in PHP?

Question

I have a structure identical to:

$sidebar_data= [
    'wp_inactive_widgets' => array(),
    'sidebar-1' => array(
        'this' => 'that',
        'this' => 'that',
        'this' => 'that'
    ),
    'sidebar-2' => array(
        'this' => 'that',
        'this' => 'that',
        'this' => 'that',
        'this' => 'that'
    ),
    'array_version' => 3
];

I'm looking to wipe out any values within the array's keys, not just the full array with unset, so, sidebar-1, sidebar-2 should be emptied, but kept, to get the desired result:

$new_sidebar_data = [
    'wp_inactive_widgets' => array(),
    'sidebar-1' => array(),
    'sidebar-2' => array(),
    'array_version' => 3
];

How can I achieve this?

Edit:

I already went through this solution:

$sidebar_data= [
    'wp_inactive_widgets' => array(),
    'sidebar-1' => array(
        'this' => 'that',
        'this' => 'that',
        'this' => 'that'
    ),
    'sidebar-2' => array(
        'this' => 'that',
        'this' => 'that',
        'this' => 'that',
        'this' => 'that'
    ),
    'array_version' => 3
];
$sidebars_widgets_original_keys = array_keys( $sidebar_data);
$sidebars_widgets_new_structure = [];

foreach( $sidebars_widgets_original_keys as $sidebars_widgets_original_key ) {
    $sidebars_widgets_new_structure[$sidebars_widgets_original_key] = array();
}

It works, but it's really ugly and feels counterintuitive to present to anyone.

All keys, or all keys not including `array_version`, or all keys which are arrays, or ??? — Nick, Aug 30 '18 at 04:36
@Nick It doesn't matter in this case, should just keep the keys. — coolpasta, Aug 30 '18 at 04:41
@Erubiel Not a duplicate. I'm looking to keep the keys of the array. — coolpasta, Aug 30 '18 at 04:42
yeah, but you can manage each children on the same way, if you are asking for the best way... but maybe you are right, maybe i should have posted it as a comment sorry... — Erubiel, Aug 30 '18 at 04:43

Jasmin Mistry · Accepted Answer · 2018-08-30T04:38:24.990

1

You can reassign empty array

$new_sidebar_data['sidebar-1'] = [];
$new_sidebar_data['sidebar-2'] = [];

more dynamic way

foreach($new_sidebar_data as &$value) {
    if (is_array($value) && count($value) > 0) {
         $value = [];
    }
}

edited Aug 30 '18 at 04:38

answered Aug 30 '18 at 04:36

Jasmin Mistry

1,459
1
18
23

Ah, I already went through this method, was just wondering if there's a cleaner way. – coolpasta Aug 30 '18 at 04:38
1

@Erubiel Its not typo its pass by reference. – Jasmin Mistry Aug 30 '18 at 04:39
@JasminMistry Sorry. It seems your solution works. Care to explain why going for the pass by reference? – coolpasta Aug 30 '18 at 04:40
@coolpasta check for is_array and count check to ensure variable is array and not empty – Jasmin Mistry Aug 30 '18 at 04:41
@coolpasta when you want to change same array inside loop then you can use &. it treat as pointer https://stackoverflow.com/questions/3307409/php-pass-by-reference-in-foreach – Jasmin Mistry Aug 30 '18 at 04:42
@JasminMistry I wonder what the performance implications of re-writing the array on the fly instead of just re-assigning the keys to a new array are. Any thoughts? – coolpasta Aug 30 '18 at 04:43
@JasminMistry my bad! – Erubiel Aug 30 '18 at 04:44

score 1 · Answer 2 · answered Aug 30 '18 at 04:44

1

Another option for you

array_walk($new_sidebar_data, function (&$value, $key) {
    if (is_array($value) && count($value) > 0) {
        $value = [];
    }
});

Works for all keys starting with "sidebar-"

answered Aug 30 '18 at 04:44

bbbbburton

63
7

How can I unset an array's children values in PHP?

2 Answers2