I have tried for a long time but couldn't find a way to merge an array in to a new one.
Mostly I get lost in looping and matching.;(
I would like to recieve a php 5 method that can do the following:
Example 1
Lets say there is an array with url's like:
Array(
'a',
'a/b/c',
'a/b/c/d/e',
'a/y',
'b/z',
'b/z/q/',
)
Every last folder of the url's is the folder where a user has the right to view.
I would like to send the array to a method that returns a new array like:
Array[](
'a/c/e'
'a/y'
'z/q'
)
The method has combined some elements of the origninal array into one element.
This because there is a match in allowed ending folders.
Example 2
Array(
'projects/projectA/books'
'projects/projectA/books/cooking/book1'
'projects/projectA/walls/wall'
'projects/projectX/walls/wall'
'projects/projectZ/'
'projects/projectZ/Wood/Cheese/Bacon'
)
I would like to get a an array like:
Array[](
'books/book1'
'wall'
'wall'
'projectZ/Bacon'
)
Then it would be great (specialy in case of the 'wall' values) to have some references to the full path's of the original array.
Do it like below:-
<?php
$array = Array(
'projects/projectA/books',
'projects/projectA/books/cooking/book1',
'projects/projectA/walls/wall',
'projects/projectX/walls/wall',
'projects/projectZ/',
'projects/projectZ/Wood/Cheese/Bacon'
);// original array
$final_array =array(); // new array variable
foreach($array as $key=>$arr){ // iterate over original array
$exploded_string = end(array_filter(explode('/',$arr))); // get last-value from the url string
foreach($array as $ar){ // iterate again the original array to compare this string withh each array element
$new_exploded_string = end(array_filter(explode('/',$ar))); // get the new-last-values from url string again
if($arr !== $ar && strpos($ar,$exploded_string) !==false){ // if both old and new url strings are not equal and old-last-value find into url string
if($exploded_string == $new_exploded_string ){ // if both new-last-value and old-last-value are equal
$final_array[] = $exploded_string;
}else{
$final_array[] = $exploded_string.'/'.$new_exploded_string ;
}
}
}
}
print_r($final_array);
Output:-https://eval.in/846738
Well, there isn't a single built-in function for this ;)
$items = array(
'projects/projectA/books',
'projects/projectA/books/cooking/book1',
'projects/projectA/walls/wall',
'projects/projectX/walls/wall',
'projects/projectZ/',
'projects/projectZ/Wood/Cheese/Bacon',
'hold/mold/gold/sold/fold',
'hold/mold/gold',
'raja/maza/saza',
'raja/maza',
'mohit/yenky/client/project',
);
echo '$items = ' . nl2br(htmlspecialchars(print_r($items, true))); //Debug
// Sort, so the shorter basePath comes before the longer subPath
usort($items, function($a, $b) {
if (strlen($a) == strlen($b)) {
return 0;
} else {
return strlen($a) > strlen($b) ? 1 : -1;
}
});
$result = array();
while($basePath = array_shift($items)) { // As long as there is a next item
$basePath = rtrim($basePath, '/'); // Right trim extra /
foreach($items as $idx => $subPath) {
if (strpos($subPath, $basePath . '/') === 0) {
// $subPath begins with $basePath
$result[] = preg_replace('#.*/#', '', $basePath) . '/' . preg_replace('#.*/#', '', rtrim($subPath, '/'));
unset($items[$idx]); // Remove item from array, so it won't be matched again
continue 2; // Continue with next while($basePath = array_shift($items))
}
}
// No subPath found, otherwise continue would have called (skipping below code)
$result[] = preg_replace('#.*/#', '', $basePath);
}
echo '$result = ' . nl2br(htmlspecialchars(print_r($result, true))); //Debug
PHPFiddle: http://phpfiddle.org/main/code/ugq9-hy0i
You can avoid using nested loops (and, actually, you should avoid):
sort($array);
$carry = array_shift($array);
$result = [];
$i = 0;
$lastItem = array_reduce($array, function ($carry, $item) use (&$result, &$i) {
$result[$i] = isset($result[$i])
? array_merge($result[$i], [basename($carry)])
: [basename($carry)];
if (strpos($item, $carry) !== 0) {
$i += 1;
}
return $item;
}, $carry);
if (!empty($lastItem)) {
$result[$i] = isset($result[$i])
? array_merge($result[$i], [basename($lastItem)])
: [basename($lastItem)];
}
$result = array_map(function ($item) {
return implode('/', $item);
}, $result);
Here is working demo.
We use array_reduce here to get access to the previously processed item. Also, PHP has function basename, that retrieves the basename. So you can use it and do not reinvent the wheel.
Related
Imagine you have a deep array like this:
<?php
$array = ['hello' => ['deep' => 'treasure']];
Then you had an array of the keys to access the string 'treasure'
['hello', 'deep'];
How do you delete the string treasure if you did not know the depth of the array till run time
Edit:
My apologises I've definitely not provided enough information for what I'm looking to achieve
Here is some code I've come up with which does what I need but uses unsafe eval (keep in mind the target destination could be an array so array_walk_recursive won't work)
function iterator_keys($iterator, $outer_data) {
$keys = array();
for ($i = 0; $i < $iterator->getDepth() + 1; $i++) {
$sub_iterator = $iterator->getSubIterator($i);
$keys[$i] = ($i == 0 && is_object($outer_data)
|| $i > 0 && is_object($last_iterator->current())) ?
'->{"' . $sub_iterator->key() . '"}' :
'["' . $sub_iterator->key() . '"]';
$last_iterator = $sub_iterator;
}
return $keys;
}
function recursive_filter($data, callable $selector_function, $iterator = NULL) {
$iterator = $iterator ?? new RecursiveIteratorIterator(
new RecursiveArrayIterator($data),
RecursiveIteratorIterator::CHILD_FIRST
);
foreach ($iterator as $key => $value) {
if ($selector_function($value, $key, $iterator)) {
eval('unset($data' . implode('', iterator_keys($iterator, $data)) . ');');
}
}
return $data;
}
The intention is to have a deep data structure a function that evalutes each node and if it matches a condition then remove it from the data structure in place, if this can be done without eval that would be amazing but so far I think PHP can't programmatically delete something that is more than one level deep
Hello I think what you want is somethings like this
<?php
$array = ['hello' => ['deep' => ['deep1' => 'treasure']]];
$keys = ["hello", "deep", "deep1"];
function remove_recursive(&$array, $keys, $level = 0)
{
if ($level >= count($keys)) {
return $array;
}
if (isset($array[$keys[$level]]) && $level == count($keys) - 1) {
unset($array[$keys[$level]]);
} elseif (isset($array[$keys[$level]])) {
$array[$keys[$level]] = remove_recursive($array[$keys[$level]], $keys, $level + 1);
}
return $array;
}
var_dump(remove_recursive($array, $keys));
Well you can try this really quick and dirty way that uses eval to achieve your goal:
$array = ['hello' => ['deep' => 'treasure']];
$keys = ['hello', 'deep'];
$expression = 'unset($array[\'' . implode('\'][\'', $keys) . '\']);';
eval($expression);
But maybe you can tell us more about your development and we can help you reorganize it somehow to avoid this problem at all.
This will set the target array element to null. Optionally you could use '':
$array = ['hello' => ['deep' => 'treasure']];
$path = ['hello', 'deep'];
$temp = &$array;
foreach($path as $key) {
$temp =& $temp[$key];
}
$temp = null;
print_r($array);
Yields:
Array
(
[hello] => Array
(
[deep] =>
)
)
I am trying to parse some data and just cant seem to figure it out myself.
I have tried using recursion and got the general idea but i cant seem to work out getting the array indexes to line up right. Here is what I have so far:
public function reverse() {
$reversedValues= array();
foreach ( $this->sorted as $key=>$value ) {
array_push( $this->reversedPaths ,$key );
array_push( $reversedValues , $value );
//print_r($this->reversed);
echo "<br />";
}
$this->reversed = $this->stringToArray($this->reversedPaths[0] , $reversedValues);
var_dump($this->reversed);
return json_encode($this->reversed , false);
}
private function stringToArray($path , $values , $count = 0) {
$separator = '/';
$pos = strpos($path, $separator);
if ($pos === false) {
//check for numbers so we know to add those to an json object
if (is_numeric($path)) {
//add it to the parent array of values...
}
$reversed = array(
$path => $values[$count],
);
return $reversed;
}
$key = substr($path, 0, $pos);
$path = substr($path, $pos + 1);
$reversed[$key] = $this->stringToArray($path , $values , $count);
$count++;
//read in next path string
if (array_key_exists( $count ,$this->reversedPaths)) {
$currentpos = strpos($this->reversedPaths[$count], $path.$separator);
$currentPath = substr($this->reversedPaths[$count], $currentpos );
$nextpos = strpos($currentPath, $separator);
if ($nextpos === false) {
} else {
$nextPath = substr($currentPath, $nextpos + 1);
$nextKey = substr($nextPath, 0, $nextpos);
echo $nextKey;
echo $nextPath;
// echo $nextKey;
//if this key equals first value of next path dont return but process recurssion again on it
if ($nextKey !== false ) {
$reversed[$key][$nextKey] = $this->stringToArray($nextPath , $values , $count);
}
}
} else {
}
return $reversed;
}
I was trying to read in the next path data to check if it is within the same array index but i just couldn't get it working. I know i am over complicating it but it doesn't seem like there is any easy way to accomplish this...
I had a crack at this. Based on the details you provided, it looks like you are trying to create a tree, like a directory structure: each / delimited string in the key represents a 'depth'. The solution I found was to create a multidimensional array for each element, parsing the current key into levels and recursively merge/replace the result into a master 'tree' array. This is what I have:
// original JSON string
$json = '{
"one/two": 3,
"one/four/0": 5,
"one/four/1": 6,
"one/four/2": 7,
"eight/nine/ten": 11
}';
// convert to a PHP multidimensional array
$array = json_decode($json, true);
// init an array to hold the final result
$tree = [];
// iterate over the array of values
// explode the key into an array 'path' tokens
// pop each off and build a multidimensional array
// finally 'merge' the result into the result array
foreach ($array as $path => $value) {
$tokens = explode('/', $path);
while (null !== ($key = array_pop($tokens))) {
$current = [$key => $value];
$value = $current;
}
$tree = array_replace_recursive($tree, $value);
}
// show the result!
print_r(json_encode($tree, JSON_PRETTY_PRINT));
Yields:
{
'one': {
'two': 3,
'four': [5, 6, 7]
},
'eight': {
'nine': {
'ten':11
}
}
}
Hope this helps :)
I need to make app with will fill array with some random values, but if in array are duplicates my app not working correctly. So I need to write script code which will find duplicates and replace them with some other values.
Okay so for example i have an array:
<?PHP
$charset=array(123,78111,0000,123,900,134,00000,900);
function arrayDupFindAndReplace($array){
// if in array are duplicated values then -> Replace duplicates with some other numbers which ones I'm able to specify.
return $ArrayWithReplacedValues;
}
?>
So result shall be the same array with replaced duplicated values.
You can just keep track of the words that you've seen so far and replace as you go.
// words we've seen so far
$words_so_far = array();
// for each word, check if we've encountered it so far
// - if not, add it to our list
// - if yes, replace it
foreach($charset as $k => $word){
if(in_array($word, $words_so_far)){
$charset[$k] = $your_replacement_here;
}
else {
$words_so_far[] = $word;
}
}
For a somewhat-optimized solution (for cases where there are not that many duplicates), use array_count_values() (reference here) to count the number of times it shows up.
// counts the number of words
$word_count = array_count_values($charset);
// words we've seen so far
$words_so_far = array();
// for each word, check if we've encountered it so far
// - if not, add it to our list
// - if yes, replace it
foreach($charset as $k => $word){
if($word_count[$word] > 1 && in_array($word, $words_so_far)){
$charset[$k] = $your_replacement_here;
}
elseif($word_count[$word] > 1){
$words_so_far[] = $word;
}
}
Here the example how to generate unique values and replace recurring values in array
function get_unique_val($val, $arr) {
if ( in_array($val, $arr) ) {
$d = 2; // initial prefix
preg_match("~_([\d])$~", $val, $matches); // check if value has prefix
$d = $matches ? (int)$matches[1]+1 : $d; // increment prefix if exists
preg_match("~(.*)_[\d]$~", $val, $matches);
$newval = (in_array($val, $arr)) ? get_unique_val($matches ? $matches[1].'_'.$d : $val.'_'.$d, $arr) : $val;
return $newval;
} else {
return $val;
}
}
function unique_arr($arr) {
$_arr = array();
foreach ( $arr as $k => $v ) {
$arr[$k] = get_unique_val($v, $_arr);
$_arr[$k] = $arr[$k];
}
unset($_arr);
return $arr;
}
$ini_arr = array('dd', 'ss', 'ff', 'nn', 'dd', 'ff', 'vv', 'dd');
$res_arr = unique_arr($ini_arr); //array('dd', 'ss', 'ff', 'nn', 'dd_2', 'ff_2', 'vv', 'dd_3');
Full example you can see here webbystep.ru
Use the function
array_unique()
See more info at http://php.net/manual/en/function.array-unique.php
$uniques = array();
foreach ($charset as $value)
$uniques[$value] = true;
$charset = array_flip($uniques);
I have following url:
www.example.com/index.php/search/search_data/Doctor:a/Gender:Male/Language:Urdu/
and I want to convert it to associative array like
$data=array(
'Doctor'=> 'a',
'Gender'=> 'Male',
'Language'=> 'Urdu'
);
I have tried to do this using codeIgniter's URI class function
$this->uri->uri_to_assoc(n)
but as it accepts the data to be separated via '/' but I am having data with ':' as separator.
please help me.
I don't think there's an easier way to do this, rather than to do it manually.
First, retrieve the total segments, loop through, see if it contains ":", then add it into the array.
$segments = $this->uri->segment_array();
$search_array = array();
foreach($segments as $segment) {
if (strpos($segment, ":") !== FALSE) {
$e_array = explode(":", $segment);
$search_array[$e_array[0]] = $e_array[1];
}
}
Running that snippet somewhere will give you desirable results, $search_array will be an associative array with key => value.
You could hack the URI.php file. Change lines 431 - 439 to;
if (strpos($seg, ":") !== FALSE) {
list($parameter, $value) = explode(':', $seg);
if ($i % 2) {
$retval[$parameter] = $value;
} else {
$retval[$parameter] = $value;
$lastval = $seg;
}
} else {
if ($i % 2) {
$retval[$lastval] = $seg;
} else {
$retval[$seg] = FALSE;
$lastval = $seg;
}
}
What would be the fastest, most efficient way to implement a search method that will return an object with a qualifying id?
Sample object array:
$array = [
(object) ['id' => 'one', 'color' => 'white'],
(object) ['id' => 'two', 'color' => 'red'],
(object) ['id' => 'three', 'color' => 'blue']
];
What do I write inside of:
function findObjectById($id){
}
The desired result would return the object at $array[0] if I called:
$obj = findObjectById('one')
Otherwise, it would return false if I passed 'four' as the parameter.
You can iterate that objects:
function findObjectById($id){
$array = array( /* your array of objects */ );
foreach ( $array as $element ) {
if ( $id == $element->id ) {
return $element;
}
}
return false;
}
Edit:
Faster way is to have an array with keys equals to objects' ids (if unique);
Then you can build your function as follow:
function findObjectById($id){
$array = array( /* your array of objects with ids as keys */ );
if ( isset( $array[$id] ) ) {
return $array[$id];
}
return false;
}
It's an old question but for the canonical reference as it was missing in the pure form:
$obj = array_column($array, null, 'id')['one'] ?? false;
The false is per the questions requirement to return false. It represents the non-matching value, e.g. you can make it null for example as an alternative suggestion.
This works transparently since PHP 7.0. In case you (still) have an older version, there are user-space implementations of it that can be used as a drop-in replacement.
However array_column also means to copy a whole array. This might not be wanted.
Instead it could be used to index the array and then map over with array_flip:
$index = array_column($array, 'id');
$map = array_flip($index);
$obj = $array[$map['one'] ?? null] ?? false;
On the index the search problem might still be the same, the map just offers the index in the original array so there is a reference system.
Keep in mind thought that this might not be necessary as PHP has copy-on-write. So there might be less duplication as intentionally thought. So this is to show some options.
Another option is to go through the whole array and unless the object is already found, check for a match. One way to do this is with array_reduce:
$obj = array_reduce($array, static function ($carry, $item) {
return $carry === false && $item->id === 'one' ? $item : $carry;
}, false);
This variant again is with the returning false requirement for no-match.
It is a bit more straight forward with null:
$obj = array_reduce($array, static function ($carry, $item) {
return $carry ?? ($item->id === 'one' ? $item : $carry);
}, null);
And a different no-match requirement can then be added with $obj = ...) ?? false; for example.
Fully exposing to foreach within a function of its own even has the benefit to directly exit on match:
$result = null;
foreach ($array as $object) {
if ($object->id === 'one') {
$result = $object;
break;
}
}
unset($object);
$obj = $result ?? false;
This is effectively the original answer by hsz, which shows how universally it can be applied.
You can use the function array_search of php like this
$key=array_search("one", array_column(json_decode(json_encode($array),TRUE), 'color'));
var_dump($array[$key]);
i: is the index of item in array
1: is the property value looking for
$arr: Array looking inside
'ID': the property key
$i = array_search(1, array_column($arr, 'ID'));
$element = ($i !== false ? $arr[$i] : null);
Well, you would would have to loop through them and check compare the ID's unless your array is sorted (by ID) in which case you can implement a searching algorithm like binary search or something of that sort to make it quicker.
My suggestion would be to first sort the arrays using a sorting algorithm (binary sort, insertion sort or quick sort) if the array is not sorted already. Then you can implement a search algorithm which should improve performance and I think that's as good as it gets.
http://www.algolist.net/Algorithms/Binary_search
This is my absolute favorite algorithm for very quickly finding what I need in a very large array, quickly. It is a Binary Search Algorithm implementation I created and use extensively in my PHP code. It hands-down beats straight-forward iterative search routines. You can vary it a multitude of ways to fit your need, but the basic algorithm remains the same.
To use it (this variation), the array must be sorted, by the index you want to find, in lowest-to-highest order.
function quick_find(&$array, $property, $value_to_find, &$first_index) {
$l = 0;
$r = count($array) - 1;
$m = 0;
while ($l <= $r) {
$m = floor(($l + $r) / 2);
if ($array[$m]->{$property} < $value_to_find) {
$l = $m + 1;
} else if ($array[$m]->{$property} > $value_to_find) {
$r = $m - 1;
} else {
$first_index = $m;
return $array[$m];
}
}
return FALSE;
}
And to test it out:
/* Define a class to put into our array of objects */
class test_object {
public $index;
public $whatever_you_want;
public function __construct( $index_to_assign ) {
$this->index = $index_to_assign;
$this->whatever_you_want = rand(1, 10000000);
}
}
/* Initialize an empty array we will fill with our objects */
$my_array = array();
/* Get a random starting index to simulate data (possibly loaded from a database) */
$my_index = rand(1256, 30000);
/* Say we are needing to locate the record with this index */
$index_to_locate = $my_index + rand(200, 30234);
/*
* Fill "$my_array()" with ONE MILLION objects of type "test_object"
*
* 1,000,000 objects may take a little bit to generate. If you don't
* feel patient, you may lower the number!
*
*/
for ($i = 0; $i < 1000000; $i++) {
$searchable_object = new test_object($my_index); // Create the object
array_push($my_array, $searchable_object); // Add it to the "$my_array" array
$my_index++; /* Increment our unique index */
}
echo "Searching array of ".count($my_array)." objects for index: " . $index_to_locate ."\n\n";
$index_found = -1; // Variable into which the array-index at which our object was found will be placed upon return of the function.
$object = quick_find($my_array, "index", $index_to_locate, $index_found);
if ($object == NULL) {
echo "Index $index_to_locate was not contained in the array.\n";
} else {
echo "Object found at index $index_found!\n";
print_r($object);
}
echo "\n\n";
Now, a few notes:
You MAY use this to find non-unique indexes; the array MUST still be sorted in ascending order. Then, when it finds an element matching your criteria, you must walk the array backwards to find the first element, or forward to find the last. It will add a few "hops" to your search, but it will still most likely be faster than iterating a large array.
For STRING indexes, you can change the arithmetic comparisons (i.e. " > " and " < " ) in quick_find() to PHP's function "strcasecmp()". Just make sure the STRING indexes are sorted the same way (for the example implementation): Alphabetically and Ascending.
And if you want to have a version that can search arrays of objects sorted in EITHER ascending OR decending order:
function quick_find_a(&$array, $property, $value_to_find, &$first_index) {
$l = 0;
$r = count($array) - 1;
$m = 0;
while ($l <= $r) {
$m = floor(($l + $r) / 2);
if ($array[$m]->{$property} < $value_to_find) {
$l = $m + 1;
} else if ($array[$m]->{$property} > $value_to_find) {
$r = $m - 1;
} else {
$first_index = $m;
return $array[$m];
}
}
return FALSE;
}
function quick_find_d(&$array, $property, $value_to_find, &$first_index) {
$l = 0;
$r = count($array) - 1;
$m = 0;
while ($l <= $r) {
$m = floor(($l + $r) / 2);
if ($value_to_find > $array[$m]->{$property}) {
$r = $m - 1;
} else if ($value_to_find < $array[$m]->{$property}) {
$l = $m + 1;
} else {
$first_index = $m;
return $array[$m];
}
}
return FALSE;
}
function quick_find(&$array, $property, $value_to_find, &$first_index) {
if ($array[0]->{$property} < $array[count($array)-1]->{$property}) {
return quick_find_a($array, $property, $value_to_find, $first_index);
} else {
return quick_find_d($array, $property, $value_to_find, $first_index);
}
}
The thing with performance of data structures is not only how to get but mostly how to store my data.
If you are free to design your array, use an associative array:
$array['one']->id = 'one';
$array['one']->color = 'white';
$array['two']->id = 'two';
$array['two']->color = 'red';
$array['three']->id = 'three';
$array['three']->color = 'blue';
Finding is then the most cheap: $one = $array['one];
UPDATE:
If you cannot modify your array constitution, you could create a separate array which maps ids to indexes. Finding an object this way does not cost any time:
$map['one'] = 0;
$map['two'] = 1;
$map['three'] = 2;
...
getObjectById() then first lookups the index of the id within the original array and secondly returns the right object:
$index = $map[$id];
return $array[$index];
Something I like to do in these situations is to create a referential array, thus avoiding having to re-copy the object but having the power to use the reference to it like the object itself.
$array['one']->id = 'one';
$array['one']->color = 'white';
$array['two']->id = 'two';
$array['two']->color = 'red';
$array['three']->id = 'three';
$array['three']->color = 'blue';
Then we can create a simple referential array:
$ref = array();
foreach ( $array as $row )
$ref[$row->id] = &$array[$row->id];
Now we can simply test if an instance exists in the array and even use it like the original object if we wanted:
if ( isset( $ref['one'] ) )
echo $ref['one']->color;
would output:
white
If the id in question did not exist, the isset() would return false, so there's no need to iterate the original object over and over looking for a value...we just use PHP's isset() function and avoid using a separate function altogether.
Please note when using references that you want use the "&" with the original array and not the iterator, so using &$row would not give you what you want.
This is definitely not efficient, O(N). But it looks sexy:
$result = array_reduce($array, function ($found, $obj) use ($id) {
return $obj['id'] == $id ? $obj : $found;
}, null);
addendum:
I see hakre already posted something akin to this.
Here is what I use. Reusable functions that loop through an array of objects. The second one allows you to retrieve a single object directly out of all matches (the first one to match criteria).
function get_objects_where($match, $objects) {
if ($match == '' || !is_array($match)) return array ();
$wanted_objects = array ();
foreach ($objects as $object) {
$wanted = false;
foreach ($match as $k => $v) {
if (is_object($object) && isset($object->$k) && $object->$k == $v) {
$wanted = true;
} else {
$wanted = false;
break;
};
};
if ($wanted) $wanted_objects[] = $object;
};
return $wanted_objects;
};
function get_object_where($match, $objects) {
if ($match == '' || !is_array($match)) return (object) array ();
$wanted_objects = get_objects_where($match, $objects);
return count($wanted_objects) > 0 ? $wanted_objects[0] : (object) array ();
};
The easiest way:
function objectToArray($obj) {
return json_decode(json_encode($obj), true);
}