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I am trying to sort it in a repeating, sequential pattern of numerical order with the largest sets first.
Sample array:
$array = [1,1,1,2,3,2,3,4,5,4,4,4,5,1,2,2,3];
In the above array, I have the highest value of 5 which appears twice so the first two sets would 1,2,3,4,5 then it would revert to the second, highest value set etc.
Desired result:
[1,2,3,4,5,1,2,3,4,5,1,2,3,4,1,2,4]
I am pretty sure I can split the array into chunks of the integer values then cherrypick an item from each subarray sequentially until there are no remaining items, but I just feel that this is going to be poor for performance and I don't want to miss a simple trick that PHP can already handle.
Here's my attempt at a very manual loop using process, the idea is to simply sort the numbers into containers for array_unshifting. I'm sure this is terrible and I'd love someone to do this in five lines or less :)
$array = array(1,1,1,2,3,2,3,4,5,4,4,4,5,1,2,2,3);
sort($array);
// Build the container array
$numbers = array_fill_keys(array_unique($array),array());
// Assignment
foreach( $array as $number )
{
$numbers[ $number ][] = $number;
}
// Worker Loop
$output = array();
while( empty( $numbers ) === false )
{
foreach( $numbers as $outer => $inner )
{
$output[] = array_shift( $numbers[ $outer ] );
if( empty( $numbers[ $outer ] ) )
{
unset( $numbers[ $outer ] );
}
}
}
var_dump( $output );
I think I'd look at this not as a sorting problem, but alternating values from multiple lists, so rather than coming up with sets of distinct numbers I'd make sets of the same number.
Since there's no difference between one 1 and another, all you actually need is to count the number of times each appears. It turns out PHP can do this for you with aaray_count_values.
$sets = array_count_values ($input);
Then we can make sure the sets are in order by sorting by key:
ksort($sets);
Now, we iterate round our sets, counting down how many times we've output each number. Once we've "drained" a set, we remove it from the list, and once we have no sets left, we're all done:
$output = [];
while ( count($sets) > 0 ) {
foreach ( $sets as $number => $count ) {
$output[] = $number;
if ( --$sets[$number] == 0 ) {
unset($sets[$number]);
}
}
}
This algorithm could be adapted for cases where the values are actually distinct but can be put into sets, by having the value of each set be a list rather than a count. Instead of -- you'd use array_shift, and then check if the length of the set was zero.
You can use only linear logic to sort using php functions. Here is optimized way to fill data structures. It can be used for streams, generators or anything else you can iterate and compare.
$array = array(1,1,1,2,3,2,3,4,5,4,4,4,5,1,2,2,3);
sort($array);
$chunks = [];
$index = [];
foreach($array as $i){
if(!isset($index[$i])){
$index[$i]=0;
}
if(!isset($chunks[$index[$i]])){
$chunks[$index[$i]]=[$i];
} else {
$chunks[$index[$i]][] = $i;
}
$index[$i]++;
}
$result = call_user_func_array('array_merge', $chunks);
print_r($result);
<?php
$array = array(1,1,1,2,3,2,3,4,5,4,4,4,5,1,2,2,3);
sort($array);
while($array) {
$n = 0;
foreach($array as $k => $v) {
if($v>$n) {
$result[] = $n = $v;
unset($array[$k]);
}
}
}
echo implode(',', $result);
Output:
1,2,3,4,5,1,2,3,4,5,1,2,3,4,1,2,4
New, more elegant, more performant, more concise answer:
Create a sorting array where each number gets its own independent counter to increment. Then use array_multisort() to sort by this grouping array, then sort by values ascending.
Code: (Demo)
$encounters = [];
foreach ($array as $v) {
$encounters[] = $e[$v] = ($e[$v] ?? 0) + 1;
}
array_multisort($encounters, $array);
var_export($array);
Or with a functional style with no global variable declarations: (Demo)
array_multisort(
array_map(
function($v) {
static $e;
return $e[$v] = ($e[$v] ?? 0) + 1;
},
$array
),
$array
);
var_export($array);
Old answer:
My advice is functionally identical to #El''s snippet, but is implemented in a more concise/modern/attractive fashion.
After ensuring that the input array is sorted, make only one pass over the array and push each re-encountered value into its next row of values. The $counter variable indicates which row (in $grouped) the current value should be pushed into. When finished looping and grouping, $grouped will have unique values in each row. The final step is to merge/flatten the rows (preserving their order).
Code: (Demo)
$grouped = [];
$counter = [];
sort($array);
foreach ($array as $v) {
$counter[$v] = ($counter[$v] ?? -1) + 1;
$grouped[$counter[$v]][] = $v;
}
var_export(array_merge(...$grouped));
I have 4 arrays, each one holds another column of a table, I would like to create one array with the data ordered per array[$i]. All arrays have the same number of values: $namesArr, $folderArr, $updatedAt, $valuesArr .
I would like my new array to be contain:
$namesArr[0], $folderArr[0], $updatedAt[0], $valuesArr[0],
$namesArr[1], $folderArr[1], $updatedAt[1], $valuesArr[1],
$namesArr[2], $folderArr[2], $updatedAt[2], $valuesArr[2],
...
I guess the solution is pretty simple, but I got stuck :(
Can anyone help?
I would do something like:
$arr = array_map(function () { return func_get_args(); },$namesArr, $folderArr, $updatedAt, $valuesArr);
You can use foreach loop to merge 4 arrays:
foreach ($namesArr as $key => $value) {
$arr[$key][] = $value;
$arr[$key][] = $folderArr[$key];
$arr[$key][] = $updatedAt[$key];
$arr[$key][] = $valuesArr[$key];
}
Thus $arr will be the merged array
<?php
$newArr = array();
for ($i = 0; $i < count($namesArr); $i++)
{
$newArr[$i][0] = $namesArr[$i];
$newArr[$i][1] = $folderArr[$i];
$newArr[$i][2] = $updatedAt[$i];
$newArr[$i][3] = $valuesArr[$i];
}
?>
Explanation
What this will do is iterate depending on how many elements there are in $namesArr.
I utilised a multidimensional array here so that the first set of square brackets is effectively the "row" in a table, and the second set of square brackets are the "column" of a table.
do the following way:
while($db->query($sql)){
$namesArr[] =$db->f('names');
$folderArr[]=$db->f('folder');
$updatedAt[]=$db->f('updated');
$valuesArr[]=$db->f('values');
}
Is there any way to get the key range of same values and make a new array?
Let's say we have an Array Like this in php :
$first_array = ['1'=>'a','2'=>'a','3'=>'a','4'=>'b','5'=>'b','6'=>'a','7'=>'a'];
How can i get this array? Is there any function for this?
$second_array = ['1-3'=>'a','4-5'=>'b','6-7'=>'a'];
Loop through it, extract the keys, generate the ranges and insert to the new array -
$first_array = ['1'=>'a','2'=>'a','3'=>'a','4'=>'b','5'=>'b'];
$flip = array();
foreach($first_array as $key => $val) {
$flip[$val][] = $key;
}
$second_array = [];
foreach($flip as $key => $value) {
$newKey = array_shift($value).' - '.end($value);
$second_array[$newKey] = $key;
}
Output
array(2) {
["1 - 3"]=>
string(1) "a"
["4 - 5"]=>
string(1) "b"
}
regarding your first question you can get range of each value using foreach() loop.
$first_array = ['1'=>'a','2'=>'a','3'=>'a','4'=>'b','5'=>'b'];
foreach($first_array as $key=>$value)
{
//do your coding here, $key is the index of the array and $value is the value at that range, you can use that index and value to perform array manipulations
}
Regarding your second question it not exactly clear what are trying to implement there. But what ever you want to do like creating a new array with modified index and other things can be done within this foreach() loop itself
I hope this helps you.
If someone is still looking for an answer, here is what I did.
Given the array
$first_array = ['0'=>'a',
'1'=>'a',
'2'=>'a',
'3'=>'a',
'4'=>'a',
'5'=>'b',
'6'=>'b',
'7'=>'a',
'8'=>'a']
I build a multidimensional array, in which each element is an array of three more elements:
[0] - The value in the first array
[1] - The key where the value starts repeating
[2] - The last key where the value stops repeating
The code
$arrayRange = [];
for($i = 0; $i < count($first_array); $i++){
if(count($arrayRange) == 0){
// The multidimensional array is still empty
$arrayRange[0] = array($first_array[$i], $i, $i);
}else{
if($first_array[$i] == $arrayRange[count($arrayRange)-1][0]){
// It's still the same value, I update the value of the last key
$arrayRange[count($arrayRange)-1][2] = $i;
}else{
// It's a new value, I insert a new array
$arrayRange[count($arrayRange)] = array($first_array[$i], $i, $i);
}
}
}
This way you get a multidimensional array like this:
$arrayRange[0] = array['a', 0, 4];
$arrayRange[1] = array['b', 5, 6];
$arrayRange[2] = array['a', 7, 8];
I have 3 arrays that return a url,title,snippet and score from 3 different search engines, the score starts at 100 for the element in the array, the second 99 and so on, I'm trying to combine all 3 into one array. If the urls match from the different arrays I want to add the scores together and then delete the duplicate url. If there is no match between the urls then I just want to put this element into the combined array.
The final combined list should contain all distinct urls with its score,title and snippet, here are my array structures
googleArray
$x=0;
$score=100;
foreach ($js->items as $item)
{
$googleArray[$x]['link'] = ($item->{'link'});
$googleArray[$x]['title'] = ($item->{'title'});
$googleArray[$x]['snippet'] = ($item->{'snippet'});
$googleArray[$x]['score'] = $score--;
$x++;
}
blekkoArray
$score = 100;
foreach ($js->RESULT as $item)
{
$blekkoArray[$i]['url'] = ($item->{'url'});
$blekkoArray[$i]['title'] = ($item->{'url_title'});
$blekkoArray[$i]['snippet'] = ($item->{'snippet'});
$blekkoArray[$i]['score'] = $score--; // assign the $score value here
$i++;
}
bingArray
foreach($jsonObj->d->results as $value)
{ $i = 0;
$bingArray[]['Url'] = ($value->{'Url'});
$bingArray[]['Title'] = ($value->{'Title'});
$bingArray[]['Description'] = ($value->{'Description'});
$bingArray[]['score'] = $score--;
$i++;
}
Any help would be great, thanks in advance
This solution depends on a couple of things to work. First, the url and score keys need to be the same, i.e. all lower case and none that are "link." Secondly, the URLs have to be normalized, because they serve as the key for the array. If there are any differences in the URLs, they will show up more than once in the final array.
$merged = array_merge($googleArray, $blekkoArray);
$merged = array_merge($merged, $bingArray);
$combined = array();
foreach ($merged as $key => $value){
$score = (isset($combined[$value['url']]['score'])) ? $value['score'] + $combined[$value['url']]['score'] : $value['score'];
$combined[$value['url']] = $value;
$combined[$value['url']]['score'] = $score;
}
If you don't want to keep the URLs as the key, add this line:
$combined = array_values($combined);
If you want to sort the array by score, you can use usort:
usort($combined, function ($a, $b){
return $b['score'] - $a['score'];
});
print_r($combined);
I need to combine two foreach statement into one for example
foreach ($categories_stack as $category)
foreach ($page_name as $value)
I need to add these into the same foreach statement
Is this possible if so how?
(I am not sure I have understood your question completely. I am assuming that you want to iterate through the two lists in parallel)
You can do it using for loop as follows :
$n = min(count($category), count($value));
for($c = 0; $c < $n; $c = $c + 1){
$categories_stack = $category[$c];
$pagename = $value[$c];
...
}
To achieve the same with foreach you need a function similar to Python's zip() function.
In Python, it would be :
for categories_stack, pagename in zip(categories, values):
print categories_stack, pagename
Since PHP doesn't have a standard zip() function, you'll have to write such a function on your own or go with the for loop solution.
You can do nested foreachs if that's what you want. But without knowing more of your data, it's impossible to say if this helps:
foreach ($categories_stack as $category) {
foreach ($page_name as $value) {
}
}
Probably you want to print out all pages in a category? That probably won't work, so can you give a bit more info on how the arrays look like and relate to each other?
This loop will continue to the length of the longest array and return null for where there are no matching elements in either of the arrays. Try it out!
$a = array(1 => "a",25 => "b", 10 => "c",99=>"d");
$b = array(15=>1,5=>2,6=>3);
$ao = new ArrayObject($a);
$bo = new ArrayObject($b);
$ai = $ao->getIterator();
$bi = $bo->getIterator();
for (
$ai->rewind(),$bi->rewind(),$av = $ai->current(),$bv = $bi->current();
list($av,$bv) =
array(
($ai->valid() ? $ai->current() : null),
($bi->valid() ? $bi->current() : null)
),
($ai->valid() || $bi->valid());
($ai->valid() ? $ai->next() : null),($bi->valid() ? $bi->next() : null))
{
echo "\$av = $av\n";
echo "\$bv = $bv\n";
}
I cannot really tell from the question exactly how you want to traverse the two arrays. For a nested foreach you simply write
foreach ($myArray as $k => $v) {
foreach ($mySecondArray as $kb => $vb {
}
}
However you can do all sorts of things with some creative use of callback functions. In this case an anonymous function returning two items from each array on each iteration. It's then easy to use the iteration value as an array or split it into variables using list() as done below.
This also has the added benefit of working regardless of key structure. I's purely based on the ordering of array elements. Just use the appropriate sorting function if the elements are out of order.
It does not worry about the length of the arrays as there is no error reported, so make sure you keep an eye out for empty values.
$a = array("a","b","c");
$b = array(1,2,3);
foreach (
array_map(
create_function(
'$a,$b', 'return array($a,$b);'
)
,$a,$b
)
as $value
)
{
list($a,$b) = $value;
echo "\$a = $a\n";
echo "\$b = $b\n";
}
Output
$a = a
$b = 1
$a = b
$b = 2
$a = c
$b = 3
Here's another one for you that stops on either of the lists ending. Same as using min(count(a),count(b). Useful if you have arrays of same length. If someone can make it continue to the max(count(a),count(b)) let me know.
$ao = new ArrayObject($a);
$bo = new ArrayObject($b);
$ai = $ao->getIterator();
$bi = $bo->getIterator();
for (
$ai->rewind(),$bi->rewind();
$av = $ai->current(),$bv=$bi->current();
$ai->next(),$bi->next())
{
echo "\$av = $av\n";
echo "\$bv = $bv\n";
}
This is where the venerable for loop comes in handy:
for(
$i = 0,
$n = sizeof($categories_stack),
$m = sizeof($page_name);
$i < $n && $i < $m;
$i++
) {
$category = $categories_stack[$i];
$value = $page_name[$i];
// do stuff here ....
}
Surely you can just merge the arrays before looping?
$data = array_merge($categories_stack, $page_name);
foreach($data AS $item){
...
}
Do the array elements have a direct correspondence with one another, i.e. is there an element in $page_name for each element in $categories_stack? If so, just iterate over the keys and values (assuming they have the same keys):
foreach ($categories_stack as $key => $value)
{
$category = $value;
$page = $page_name[$key];
// ...
}
Could you just nest them with variables outside the scope of the foreach, or prehaps store the content as an array similar to a KVP setup? My answer is vague but I'm not really sure why you're trying to accomplish this.