Given this multidimensional array, I'm trying to retrieve the value of one of the child keys:
$movieCast = Array(
'1280741692' => Array(
...
, 'userid' => 62
, 'country_id' => '00002'
...
)
, '1280744592' => Array(
...
, 'userid' => 62
, 'country_id' => '00002'
...
)
)
How can I retrieve the value of country_id?
The top-level array key could be anything and the value of country_id will always be the same for a specific user. In this example, user #62's country_id will always be 00002.
You have to iterate through the outer array:
foreach ($outer as $inner) {
//do something with $inner["country_id"]
}
Another option is to build an array with the contry_ids (example uses PHP >=5.3 functionality, but that can be worked around easily in earlier versions):
array_map(function ($inner) { return $inner["country_id"]; }, $outer);
EDIT If the ids are all the same, even easier. Do:
$inner = reset($outer); //gives first element (and resets array pointer)
$id = $inner["country_id"];
a more general-purpose solution using php 5.3:
function pick($array,$column) {
return array_map(
function($record) use($column) {
return $record[$column];
},
$array
);
}
You need to use this:
array_column($movieCast, 'country_id')
The result will be:
array (
0 => '00002',
1 => '00002',
)
Related
This question already has answers here:
How to filter an array by a condition
(9 answers)
Closed 7 months ago.
How can I remove an item based on key for example, $array[testing3] or based on value, for example, Template3 from the below array in php.
$array = array(
'mentor' => 'Template',
'mentor1' => 'Template1',
'testing' => 'Template2',
'testing3' => 'Template3',
'testing4' => 'Template4',
'testing5' => 'Template5',
'testing6' => 'Template6'
);
Let's use array_filter() to achieve the goal.
$array = array(
'mentor' => 'Template',
'mentor1' => 'Template1',
'testing' => 'Template2',
'testing3' => 'Template3',
'testing4' => 'Template4',
'testing5' => 'Template5',
'testing6' => 'Template6'
);
Remove an item in an array, for example, Template3
$filtered_array1 = array_filter($array, function($val) {
return 'Template3' != $val;
});
print_r($filtered_array1);
Remove all elements in an array except Template3 from the array
$filtered_array2 = array_filter($array, function($val) {
return 'Template3' == $val;
});
print_r($filtered_array2);
So far, we used value to filter an array. You can filter an array based on key too. You need to use 3rd argument to the function. There two options for the 3rd argument - ARRAY_FILTER_USE_KEY and ARRAY_FILTER_USE_BOTH. You may use one of them. Let's use ARRAY_FILTER_USE_KEY flag to remove an item based on key, for example, testing3:
$filtered_array3 = array_filter($array, function($key) {
return 'testing3' != $key;
}, ARRAY_FILTER_USE_KEY);
print_r($filtered_array3);
To know more about array_filter() function please refer to this doc
You can use unset() to achieve this:
unset(myArray['testing3']);
You can use unset (https://www.php.net/unset)
$array = array(
'mentor' => 'Template',
'mentor1' => 'Template1',
'testing' => 'Template2',
'testing3' => 'Template3',
'testing4' => 'Template4',
'testing5' => 'Template5',
'testing6' => 'Template6');
unset($array['testing3']);
or if you need to find it by the value you can use the array_search (https://www.php.net/array-search)
// Remove the element if it exists
if($element = array_search("Template3",$array)){
unset($array[$element]);
}
To answer the question brought up in the comments about keeping only the array element you're looking for:
use array_search and overwrite your array (or create a new array from it).
$array = array_search('Template3', $array);
I wrote this function to get a subset of an array. Does php have a built in function for this. I can't find one in the docs. Seems like a waste if I'm reinventing the wheel.
function array_subset($array, $keys) {
$result = array();
foreach($keys as $key){
$result[$key] = $array[$key];
}
return $result;
}
I always want this too. Like a PHP version of Underscore's pick.
It's ugly and counter-intuitive, but what I sometimes do is this (I think this may be what prodigitalson was getting at):
$a = ['foo'=>'bar', 'zam'=>'baz', 'zoo'=>'doo'];
// Extract foo and zoo but not zam
print_r(array_intersect_key($a, array_flip(['foo', 'zoo'])));
/*
Array
(
[foo] => bar
[zoo] => doo
)
*/
array_intersect_key returns all the elements of the first argument whose keys are present in the 2nd argument (and all subsequent arguments, if any). But, since it compares keys to keys, I use array_flip for convenience. I could also have just used ['foo' => null, 'zoo' => null] but that's even uglier.
array_diff_key and array_intersect_key are probably what you want.
There is no direct function I think in PHP to get a subset from an array1 with compare to another array2 where the values are the list of key name which we fetch.
Like: array_only($array1, 'field1','field2');
But this way can be achieved the same.
<?php
$associative_array = ['firstname' => 'John', 'lastname' => 'Smith', 'DOB' => '2000-10-10', 'country' => 'Ireland' ];
$subset = array_intersect_key( $associative_array, array_flip( [ 'lastname', 'country' ] ) );
print_r( $subset );
// Outputs...
// Array ( [lastname] => Smith [country] => Ireland );
I have this array:
$datas = array(
array(
'id' => '1',
'country' => 'Canada',
'cities' => array(
array(
'city' => 'Montreal',
'lang' => 'french'
),
array(
'city' => 'Ottawa',
'lang' => 'english'
)
)
)
);
Question 1:
How can I get the the country name when I have the id ?
I tried: $datas['id'][1] => 'country'
Question 2:
How can I loop in the cities when I have the id ?
I tried:
foreach ($datas as $data => $info) {
foreach ($info['cities'] as $item) {
echo '<li>'.$item['city'].'</li>';
}
}
Thanks a lot.
You have the ID of the array you want analyse, but your array is structured as a map, meaning that there are no keys in the outer array. You will therefore have to iterate the array first to find the object you are looking for.
While the first approach would be to search for the object that has the ID you are looking for, i suggest you map your arrays with their IDs. To do that, you can use two PHP array functions: array_column and array_combine.
array_column can extract a specific field of each element in an array. Since you have multiple country objects, we want to extract the ID from it to later use it as a key.
array_combine takes two arrays with the same size to create a new associative array. The values of the first array will then be used as keys, while the ones of the second array will be used as values.
$mappedCountries = array_combine(array_column($datas, 'id'), $datas);
Assuming that the key 1 is stored in the variable $key = 1;, you can afterwards use $mappedCountries[$key]['country'] to get the name of the country and $mappedCountries[$key]['cities'] to get the cities, over which you can then iterate.
if there might be many arrays in $datas and you want to find one by id (or some other key) you can do something like this:
function search($datas, $key, $value) {
foreach($datas as $data) {
if ($data[$key] === $value) {
return $data;
}
}
So if you want to find where id = 1
$result = search($datas, 'id', '1');
and then you can get country echo $result['country'] or whatever you need.
I am new to using multidimensional arrays with php, I have tried to stay away from them because they confused me, but now the time has come that I put them to good use. I have been trying to understand how they work and I am just not getting it.
What I am trying to do is populate results based on a string compare function, once I find some match to an 'item name', I would like the first slot to contain the 'item name', then I would like to increment the priority slot by 1.
So when when I'm all done populating my array, it is going to have a variety of different company names, each with their respective priority...
I am having trouble understanding how to declare and manipulate the following array:
$matches = array(
'name'=>array('somename'),
'priority'=>array($priority_level++)
);
So, in what you have, your variable $matches will point to a keyed array, the 'name' element of that array will be an indexed array with 1 entry 'somename', there will be a 'priority' entry with a value which is an indexed array with one entry = $priority_level.
I think, instead what you probably want is something like:
$matches[] = array(name => 'somename', $priority => $priority_level++);
That way, $matches is an indexed array, where each index holds a keyed array, so you could address them as:
$matches[0]['name'] and $matches[0]['priority'], which is more logical for most people.
Multi-dimensional arrays are easy. All they are is an array, where the elements are other arrays.
So, you could have 2 separate arrays:
$name = array('somename');
$priority = array(1);
Or you can have an array that has these 2 arrays as elements:
$matches = array(
'name' => array('somename'),
'priority' => array(1)
);
So, using $matches['name'] would be the same as using $name, they are both arrays, just stored differently.
echo $name[0]; //'somename';
echo $matches['name'][0]; //'somename';
So, to add another name to the $matches array, you can do this:
$matches['name'][] = 'Another Name';
$matches['priority'][] = 2;
print_r($matches); would output:
Array
(
[name] => Array
(
[0] => somename
[1] => Another Name
)
[priority] => Array
(
[0] => 1
[1] => 2
)
)
In this case, could this be also a solution with a single dimensional array?
$matches = array(
'company_1' => 0,
'company_2' => 0,
);
if (isset($matches['company_1'])) {
++$matches['company_1'];
} else {
$matches['company_1'] = 1;
}
It looks up whether the name is already in the list. If not, it sets an array_key for this value. If it finds an already existing value, it just raises the "priority".
In my opinion, an easier structure to work with would be something more like this one:
$matches = array(
array( 'name' => 'somename', 'priority' => $priority_level_for_this_match ),
array( 'name' => 'someothername', 'priority' => $priority_level_for_that_match )
)
To fill this array, start by making an empty one:
$matches = array();
Then, find all of your matches.
$match = array( 'name' => 'somename', 'priority' => $some_priority );
To add that array to your matches, just slap it on the end:
$matches[] = $match;
Once it's filled, you can easily iterate over it:
foreach($matches as $k => $v) {
// The value in this case is also an array, and can be indexed as such
echo( $v['name'] . ': ' . $v['priority'] . '<br>' );
}
You can also sort the matched arrays according to the priority:
function cmp($a, $b) {
if($a['priority'] == $b['priority'])
return 0;
return ($a['priority'] < $b['priority']) ? -1 : 1;
}
usort($matches, 'cmp');
(Sourced from this answer)
$matches['name'][0] --> 'somename'
$matches['priority'][0] ---> the incremented $priority_level value
Like David said in the comments on the question, it sounds like you're not using the right tool for the job. Try:
$priorities = array();
foreach($companies as $company) {
if (!isset($priorities[$company])) { $priorities[$company] = 0; }
$priorities[$company]++;
}
Then you can access the priorities by checking $priorities['SomeCompanyName'];.
I wrote this function to get a subset of an array. Does php have a built in function for this. I can't find one in the docs. Seems like a waste if I'm reinventing the wheel.
function array_subset($array, $keys) {
$result = array();
foreach($keys as $key){
$result[$key] = $array[$key];
}
return $result;
}
I always want this too. Like a PHP version of Underscore's pick.
It's ugly and counter-intuitive, but what I sometimes do is this (I think this may be what prodigitalson was getting at):
$a = ['foo'=>'bar', 'zam'=>'baz', 'zoo'=>'doo'];
// Extract foo and zoo but not zam
print_r(array_intersect_key($a, array_flip(['foo', 'zoo'])));
/*
Array
(
[foo] => bar
[zoo] => doo
)
*/
array_intersect_key returns all the elements of the first argument whose keys are present in the 2nd argument (and all subsequent arguments, if any). But, since it compares keys to keys, I use array_flip for convenience. I could also have just used ['foo' => null, 'zoo' => null] but that's even uglier.
array_diff_key and array_intersect_key are probably what you want.
There is no direct function I think in PHP to get a subset from an array1 with compare to another array2 where the values are the list of key name which we fetch.
Like: array_only($array1, 'field1','field2');
But this way can be achieved the same.
<?php
$associative_array = ['firstname' => 'John', 'lastname' => 'Smith', 'DOB' => '2000-10-10', 'country' => 'Ireland' ];
$subset = array_intersect_key( $associative_array, array_flip( [ 'lastname', 'country' ] ) );
print_r( $subset );
// Outputs...
// Array ( [lastname] => Smith [country] => Ireland );