Traversing all values of an array of arrays - php

N in this question means any arbitrary number of any size and is not necessarily (but could be) the same. I have an array with N number of key => value pairs. These key => value pairs can also contain another array of size N with N number of key => value pairs. This array can be of N depth, meaning any key => value pair in the array could map to another array.How do I get all the values of this array (storing them in a new, 1 dimensional array), ignoring the keys in the key => value pairs?

array-walk-recursive
rob at yurkowski dot net 26-Oct-2010
06:16
If you don't really particularly
care about the keys of an array, you
can capture all values quite simply:
$sample = array(
'dog' => 'woof',
'cat' => array(
'angry' => 'hiss',
'happy' => 'purr'
),
'aardvark' => 'kssksskss'
);
$output = array();
// Push all $val onto $output.
array_walk_recursive($sample, create_function('$val, $key, $obj', 'array_push($obj, $val);'), &$output);
// Printing echo nl2br(print_r($output, true));
/*
* Array
* (
* [0] => woof
* [1] => hiss
* [2] => purr
* [3] => kssksskss
* )
*/

You could do smt like this:
$output = array();
function genArray( $arr ) {
global $output;
foreach( $arr as $key => $val ) {
if( is_array($val) )
genArray( $val );
else
output[$key] = $val;
}
}
genArray( $myArray );
Instead of recursion, using global variable and function, it could be done via loops, but this is just a general idea, and probably needs a little of your attention, anyway. That should be a good thing :)

There are a ton of solutions in the comments of the array_values php doc.
http://www.php.net/manual/en/function.array-values.php

Related

How to get integer value from array:php

When I do a print_r on my $_POST, I have an array that may look like this:
Array
(
[action] => remove
[data] => Array
(
[row_1] => Array
(
[DT_RowId] => row_1
[name] => Unit 1
[item_price] => 150.00
[active] => Y
[taxable] => Y
[company_id] => 1
)
)
)
The row_1 value can be anything formatted like row_?
I want that number as a string, whatever the number is. That key and the DT_RowID value will always be the same if that helps.
Right now I am doing this, but it seems like a bad way of doing it:
//the POST is a multidimensinal array... the key inside the 'data' array has the id in it, like this: row_2. I'm getting the key value here and then removing the letters to get only the id nummber.
foreach ($_POST['data'] AS $key => $value) {
$id_from_row_value = $key;
}
//get only number from key = still returning an array
preg_match_all('!\d+!', $id_from_row_value, $just_id);
//found I had to use [0][0] since it's still a multidimensional array to get the id value
$id = $just_id[0][0];
It works, but I'm guessing there's a faster way of getting that number from the $_POST array.
<?php
$array = [
'data' => [
'row_1' => [],
'row_2' => [],
]
];
$nums = [];
foreach ($array['data'] as $key => $val) {
$nums[] = preg_replace('#[^\d]#', '', $key);
}
var_export($nums);
Outputs:
array (
0 => '1',
1 => '2',
)
Please remember that regular expressions, used in preg_match are not the fastest solution. What I would do is split the string by _ and take the second part. Like that:
$rowId = explode("_", "row_2")[1];
And put that into your loop to process all elements.

Access array by its numeric index

I have this array
Array ( [name] => guardian [url] => http://www.guardian.co.uk )
Array ( [name] => cnn [url] => http://www.cnn.com )
which i am accessing like
$das_repeat = get_post_meta($post->ID, 'repeatable_fields', true);
foreach ( $das_repeat as $fiel ) {
echo $fiel['name'].'<br/>';
//print_r($fiel);
}
However, i am very interested in accessing each value by its numeric index.How can i reindex $fiel['name'] to allow me access each value by its index?.
Your array does not have numeric indices, it does not really make sense to access it by numeric indices. You can strip all the keys out and reindex the array numerically:
$reindexed = array_values($das_repeat);
However, again, it doesn't really make sense to do so. If you want to iterate over the array without knowing its keys, you're already doing that using foreach.
To re-index an array you can use array_values.
$array = array(
'name' => 'A name',
'attr2' => 'Attr 2'
);
$array = array_values($array);
var_dump($array);
Result:
array
0 => string 'A name' (length = 6)
1 => string 'Attr 2' (length = 6)
Although, as #deceze pointed out, this has the potential to cause bugs and/or unexpected behavior in your code, so use wisely. For example, think about what will happen if, for some reason, the 1st post meta will be deleted. All the information you show will be wrong.
Note: Is not recursive
foreach ( $das_repeat as $id => $fiel ) {
echo $fiel['name'].'<br/>';
//print_r($fiel);
// $id not contains the index
}
Use array_values.
foreach ( $das_repeat as $fiel ) {
$field = array_values($fiel);
echo $field[0]; //will output guardian and then cnn
}
As other answers say, you can use array_values to create a new array with the same values, but numeric indices. If you want to keep the associative array as it is, but also access it numerically, you could do this:
$keys = array_keys($das_repeat);
$elementN = $das_repeat[$keys[$N]];

How to convert a 2-dim array of strings into 1-dim array of trimmed, unique values?

I have an array whose values are all arrays of a specific format that looks like this:
Array
(
[0] => Array
(
[0] => '8227'
[1] => ' 8138'
)
[1] => Array
(
[0] => '8227'
[1] => ' 8138'
[2] => ' 7785'
)
)
and I would like to have this:
Array
(
[0] => 8227
[1] => 8138
[2] => 7785
)
How can I do this ?
$result = array();
foreach ($input as $sub) { // Loop outer array
foreach ($sub as $val) { // Loop inner arrays
$val = trim($val);
if (!in_array($val, $result)) { // Check for duplicates
$result[] = $val; // Add to result array
}
}
}
$result = array();
foreach($array as $arr){
$result = array_merge($result, $arr);
}
$result = array_unique($result);
array_merge_recursive() can be used to flatten the array. Then, array_unique() to get the unique values, with array_values() to "reindex" the resultant array.
$flat = call_user_func_array('array_merge_recursive', $subject);
$uniq = array_values(array_unique($flat));
<?php
$array = array(
0 => array(
0 => 8227,
1 => 8138
),
1 => array(
0 => 8227,
1 => 8138,
2 => 7785
)
);
$newArray = array();
array_walk_recursive($array, function($item, $key) use(&$newArray) {
if(!in_array($item, $newArray)) {
$newArray[] = $item;
}
});
print_r($newArray);
?>
I don't like the idea of iterated calls of in_array() since it can cause a bit of drag on big arrays.
Now, my methods to follow are probably not going to set any speed records (I didn't bother to benchmark), but I thought I would post a couple of unorthodox approaches in case they may inspire future readers.
Method #1:
convert the multi-dimensional array to a json string
split the string on all non-digital substrings (this also trims the values)
eliminate duplicates using array_flip()
re-index the resultant array using array_keys() (output values are integer-type)
Method #2:
convert the multi-dimensional array to a json string
extract the words (which in this case include numbers and there aren't any letters to worry about)
eliminate duplicates using array_flip()
reindex the resultant array using array_keys() (output values are integer-type)
Code: (Demo)
$array = [['8227', '8138'], [' 8227', ' 8138', ' 7785']];
echo "regex method: ";
var_export(
array_keys(
array_flip(
preg_split(
'/\D+/',
json_encode($array),
0,
PREG_SPLIT_NO_EMPTY
)
)
)
);
echo "\n\nnon-regex method: ";
var_export(
array_keys(
array_flip(
str_word_count(
json_encode($array),
1,
'0..9'
)
)
)
);
Output:
regex method: array (
0 => 8227,
1 => 8138,
2 => 7785,
)
non-regex method: array (
0 => 8227,
1 => 8138,
2 => 7785,
)
If either of these methods perform well, it will be because they don't make iterated function calls.
p.s. Okay, because I was curious, I just did a very small / unofficial speed test on my two methods and DaveRandom's method (only 1000 iterations using the OP's data - I didn't want to abuse 3v4l.org) and...
Method #1 ran about as fast as Method #2
Both Method #1 and Method #2 ran faster than DaveRandom's method.
Again, I'll state that fabricated tests for micro-optimization may be pointless and real tests should be done on your REAL data IF it is actually important. If you merely prefer the logical flow of another answer on this page, I totally respect that.

PHP - Create a single array from a multidimensional array based on key name

I know there are a lot of answers on multi-dimensional arrays but I couldn't find what I was looking for exactly. I'm new to PHP and can't quite get my head around some of the other examples to modify them. If someone could show me the way, it would be much appreciated.
An external service is passing me the following multidimensional array.
$mArray = Array (
[success] => 1
[errors] => 0
[data] => Array (
[0] => Array (
[email] => me#example.com
[id] => 123456
[email_type] => html
[ip_opt] => 10.10.1.1
[ip_signup] =>
[member_rating] => X
[info_changed] => 2011-08-17 08:56:51
[web_id] => 123456789
[language] =>
[merges] => Array (
[EMAIL] => me#example.com
[NAME] => Firstname
[LNAME] => Lastname
[ACCOUNT] => ACME Ltd
[ACCMANID] => 123456adc
[ACCMANTEL] => 1234 123456
[ACCMANMAIL] => an.other#example.com
[ACCMANFN] => Humpty
[ACCMANLN] => Dumpty
)
[status] => unknown
[timestamp] => 2011-08-17 08:56:51
[lists] => Array ( )
[geo] => Array ( )
[clients] => Array ( )
[static_segments] => Array ( )
)
)
)
The only information I'm interested in are the key/value pairs that are held in the array under the key name 'merges'. It's about the third array deep. The key name of the array will always be called merges but there's no guarantee that its location in the array won't be moved. The number of key/value pairs in the merges array is also changeable.
I think what I need is a function for array_walk_recursive($mArray, "myfunction", $search);, where $search holds the string for the Key name (merges) I'm looking for. It needs to walk the array until it finds the key, check that it holds an array and then (preserving the keys), return each key/value pair into a single array.
So, for clarity, the output of the function would return:
$sArray = Array (
[EMAIL] => me#example.com
[NAME] => Firstname
[LNAME] => Lastname
[ACCOUNT] => ACME Ltd
[ACCMANID] => 123456adc
[ACCMANTEL] => 1234 123456
[ACCMANMAIL] => an.other#example.com
[ACCMANFN] => Humpty
[ACCMANLN] => Dumpty
)
I can then move on to the next step in my project, which is to compare the keys in the single merges array to element IDs obtained from an HTML DOM Parser and replace the attribute values with those contained in the single array.
I probably need a foreach loop. I know I can use is_array to verify if $search is an array. It's joining it all together that I'm struggling with.
Thanks for your help.
Would this work?
function find_merges($arr)
{
foreach($arr as $key => $value){
if($key == "merges") return $value;
if(is_array($value)){
$ret = find_merges($value);
if($ret) return $ret;
}
}
return false;
}
It would do a depth-first search until you either ran out of keys or found one with the value merges. It won't check to see if merges is an array though. Try that and let me know if that works.
Here is a general purpose function that will work it's way through a nested array and return the value associated with the first occurance of the supplied key. It allows for integer or string keys. If no matching key is found it returns false.
// return the value a key in the supplied array
function get_keyval($arr,$mykey)
{
foreach($arr as $key => $value){
if((gettype($key) == gettype($mykey)) && ($key == $mykey)) {
return $value;
}
if(is_array($value)){
return get_keyval($value,$mykey);
}
}
return false;
}
// test it out
$myArray = get_keyval($suppliedArray, "merges");
foreach($myArray as $key => $value){
echo "$key = $value\n";
}
A recursive function can do this. Returns the array or FALSE on failure.
function search_sub_array ($array, $search = 'merges') {
if (!is_array($array)) return FALSE; // We're not interested in non-arrays
foreach ($array as $key => $val) { // loop through array elements
if (is_array($val)) { // We're still not interested in non-arrays
if ($key == $search) {
return $val; // We found it, return it
} else if (($result = search_sub_array($array)) !== FALSE) { // We found a sub-array, search that as well
return $result; // We found it, return it
}
}
}
return FALSE; // We didn't find it
}
// Example usage
if (($result = search_sub_array($myArray,'merges')) !== FALSE) {
echo "I found it! ".print_r($result,TRUE);
} else {
echo "I didn't find it :-(";
}
So you want to access an array within an array within an array?
$mergeArray = NULL;
foreach($mArray['data'] as $mmArray)
$mergeArray[] = $mmArray['merges'];
Something like that? If merges is always three deep down, I don't see why you need recursion. Otherwise see the other answers.
Here's another approach, mostly because I haven't used up my iterator quota yet today.
$search = new RegexIterator(
new RecursiveIteratorIterator(
new ParentIterator(new RecursiveArrayIterator($array)),
RecursiveIteratorIterator::SELF_FIRST),
'/^merges$/D', RegexIterator::MATCH, RegexIterator::USE_KEY
);
$search->rewind();
$merges = $search->current();
array_walk_recursive() is brilliant for this task! It doesn't care what level the key-value pairs are on and it only iterates the "leaf nodes" so there is not need to check if an element contains a string. Inside of the function, I am merely making a comparison on keys versus the array of needles to generate a one-dimensional result array ($sArray).
To be clear, I am making an assumption that you have predictable keys in your merges subarray.
Code: (Demo)
$needles=['EMAIL','NAME','LNAME','ACCOUNT','ACCMANID','ACCMANTEL','ACCMANMAIL','ACCMANFN','ACCMANLN'];
array_walk_recursive($mArray,function($v,$k)use(&$sArray,$needles){if(in_array($k,$needles))$sArray[$k]=$v;});
var_export($sArray);
Output:
array (
'EMAIL' => 'me#example.com',
'NAME' => 'Firstname',
'LNAME' => 'Lastname',
'ACCOUNT' => 'ACME Ltd',
'ACCMANID' => '123456adc',
'ACCMANTEL' => '1234 123456',
'ACCMANMAIL' => 'an.other#example.com',
'ACCMANFN' => 'Humpty',
'ACCMANLN' => 'Dumpty',
)

Find the key of a corresponding array value

I have an array like this. What i want is to get the value of the index for specific values. ie, i want to know the index of the value "UD" etc.
Array
(
[0] => LN
[1] => TYP
[2] => UD
[3] => LAG
[4] => LO
)
how can i do that??
array_search function is meant for that usage
snipet:
$index = array_search('UD', $yourarray);
if($index === false){ die('didn\'t found this value!'); }
var_dump($index);
Use array_search:
$array = array(0 => 'LN', 1 => 'TYP', 2 => 'UD', 3 => 'LAG', 4 => 'LO');
$key = array_search('UD', $array); // $key = 2;
if ($key === FALSE) {
// not found
}
Your best bet is:
array_keys() returns the keys, numeric and string, from the input array.
If the optional search_value is specified, then only the keys for that value are returned. Otherwise, all the keys from the input are returned.
$array = array(0 => 'LN', 1 => 'TYP', 2 => 'UD', 3 => 'LAG', 4 => 'LO');
print_r(array_keys($array, "UD"));
Array
(
[0] => 2
)
Possible considerations for not using array_search()
array_search() If needle is found in haystack more than once, the first matching key is returned. To return the keys for all matching values, use array_keys() with the optional search_value parameter instead.
I suggest array_flip:
$value = "UD";
$new = array_flip($arr);
echo "result: " . $new[$value];
Just a note: some of these array_* functions are substantially more useful in PHP 5.3 with the addition of anonymous functions. You can now do things like:
$values = array_filter($userArray, function($user)
{
// If this returns true, add the current $user object to the resulting array
return strstr($user->name(),"ac");
});
Which will return all elements in our imaginary array of user objects that contain "ac" ("Jack","Jacob") in their name.
This has been possible in the past with create function, or simply by defining a function beforehand, but this syntax make it a lot more accessible.
http://ca2.php.net/manual/en/functions.anonymous.php
$array = Array(0 => LN, 1 => TYP, 2 => UD, 3 => LAG, 4 => LO);
$arrtemp = array_keys($array,'UD');
echo 'Result : '.$arrtemp[0];
I use array_keys to find it.

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