Fetch array element with highest prefix value - php

I have an array like this. I want to retreive the array element with highest version number.
Array(
[0] => "ARRELEMENT_test",
[1] => "ARRELEMENT_test_v",
[2] => "ARRELEMENT_test_v5",
[3] => "ARRELEMENT_test_v1",
[4] => "ARRELEMENT_test_v2",
[5] => "ARRELEMENT_test_v3"
)
Here it should return ARRELEMENT_test_v3 array element. Is there are any predefined function so that we can achieve this. I am trying like this.
function findPrefix($array) {
$i = 1;
while ($i < strlen($array[0])) {
$match = substr($array[0], 0, $i);
foreach ($array as $arr) {
$nextmatch = substr($arr, 0, $i-1);
if ($match < $nextmatch ) {
//return array element with highest prefix
}
}
$i++; // increase string length
}
}

function getIndexOfMaxNumber($arr){
//get the numeric value from the string and store it in an array
foreach($arr as $key=>$val){
preg_match('!\d+!', $val, $match);
if($match){
$index[$key]= $match[0];
}
}
//Sort an array and maintain index association
arsort($index);
//Set the internal pointer of an array to its first element
reset($index);
$first_key = key($index);
return $first_key;
}
$maxIndex = getIndexOfMaxNumber($arr);
echo $arr[$maxIndex];
Demo

Related

Split flat array into grouped subarrays containing values from consecutive key in the input array

I have an array from array_diff function and it looks like below:
Array
(
[0] => world
[1] => is
[2] => a
[3] => wonderfull
[5] => in
[6] => our
)
As you can see, we have a gap between the keys #3 and #5 (i.e. there is no key #4).
How can I split that array into 2 parts, or maybe more if there are more gaps?
The expected output would be:
Array
(
[0] => Array
(
[0] => world
[1] => is
[2] => a
[3] => wonderfull
)
[1] => Array
(
[0] => in
[1] => our
)
)
You can use old_key,new_key concept to check that there difference is 1 or not? if not then create new index inside you result array otherwise add the values on same index:-
<?php
$arr = Array(0 => 'world',1 => 'is',2 => 'a',3 => 'wonderfull',5 => 'in',6 => 'our');
$new_array = [];
$old_key = -1;
$i = 0;
foreach($arr as $key=>$val){
if(($key-$old_key) ==1){
$new_array[$i][] = $val;
$old_key = $key;
}
if(($key-$old_key) >1){
$i++;
$new_array[$i][] = $val;
$old_key = $key;
}
}
print_r($new_array);
https://3v4l.org/Yl9rp
You can make use of the array internal pointer to traverse the array.
<?php
$arr = Array(0=>"world",1=>"is",2=>"a",3=>"wonderfull",5=>"in",6=>"our");
print_r($arr);
$result = Array();
$lastkey;
while($word = current($arr))
{
$key = key($arr);
if(isset($lastkey) && $key == $lastkey + 1)
{
$result[count($result) - 1][] = $word;
}
else
{
$result[] = Array($word);
}
$lastkey = $key;
next($arr);
}
print_r($result);
?>
This task is a perfect candidate for a reference variable. You unconditionally push values into a designated "bucket" -- in this case a subarray. You only conditionally change where that bucket is in the output array.
There are two important checks to make when determining if a new incremented key should be generated:
if it is not the first iteration and
the current key minus (the previous key + 1) does not equal 0.
Code: (Demo)
$nextKey = null;
$result = [];
foreach ($array as $key => $val) {
if ($nextKey === null || $key !== $nextKey) {
unset($ref);
$result[] = &$ref;
}
$ref[] = $val;
$nextKey = $key + 1;
}
var_export($result);
This solution generates an indexed array starting from zero with my sample input and uses only one if block. In contrast, AliveToDie's solution generates a numerically keyed array starting from 1 and uses two condition blocks containing redundant lines of code.

Conversion of an array from one form to another

I have an array.
Array
(
[0] => 1_4
[1] => 1_1
[2] => 1_2
[3] => 2_3
[4] => 2_5
)
I want to convert it to
Array
(
[1] => Array (4,1,2)
[2] => Array (3,5)
)
Can any1 help me in this? The new keys (1 and 2) are the distinct values from 1st part of array before _.
If the underscore will always be the unique split you could explode on underscore and append results to a new array.
$before = ['1_4','1_1','1_2','2_3','2_5'];
$after = [];
foreach ($before as $entry) {
$index = explode('_',$entry);
$after[$index[0]][] = $index[1];
}
return $after;
Quick and dirty...
foreach($array as $value){ // Loop your current array
$arr = substr($value,0); // Get the character before _, 1 or 2
$val = substr($value,2); // Get character after _, 1,2,3,4 or 5
if($arr == 1){ // if 1_, put into first new array
$newArray[0][] = $val;
}else{
$newArray[1][] = $val; // Put into second array else
}
}
print_r($newArray);
Maybe try something like this?
foreach ($array as $element( {
$kv_pair = explode("_", $element, 2);
if (array_key_exists($kv_pair[0])) {
array_push($new_array[$kv_pair[0]], $kv_pair[1]);
} else {
$new_array[$kv_pair[0]] = [$kv_pair[1]];
}
}

Concat values of array with same key

I want to concat values of array with same key
Example:
[0] => Array
(
[0] => A
[1] => XYZ
)
[1] => Array
(
[0] => B
[1] => ABC
)
[2] => Array
(
[0] => A
[1] => LMN
)
[3] => Array
(
[0] => B
[1] => PQR
)
)
Expected output:
[0] => Array
(
[0] => A
[1] => XYZ,LMN
)
[1] => Array
(
[0] => B
[1] => ABC,PQR
)
)
A simple solution uses the PHP function array_reduce():
// The input array you posted in the question
$input = array(
array('A', 'XYZ'),
array('B', 'ABC'),
array('A', 'LMN'),
array('B', 'PQR'),
);
// Reduce the array to a new array that contains the data aggregated as you need
$output = array_reduce(
// Process each $item from $input using a callback function
$input,
// The callback function processes $item; the partial result is $carry
function (array $carry, array $item) {
// Extract the key into a variable
$key = $item[0];
// If the key was encountered before
// then a partial entry already exists in $carry
if (isset($carry[$key])) {
// Append the desired value to the existing entry
$carry[$key][1] .= ','.$item[1];
} else {
// Create a new entry in $carry (copy $item to key $key for quick retrieval)
$carry[$key] = $item;
}
// Return the updated $carry
return $carry;
},
// Start with an empty array (it is known as $carry in the callback function)
array()
);
// $output contains the array you need
Try this:
$final = array();
foreach ($array_items as $item)
{
$key = $item[0];
$found_index = -1;
for ($i=0; $i<count($final); $i++)
{
if ($key == $final[$i][0])
{
$found_index = $i;
break;
}
}
if ($found_index == -1)
{
$final_item = array();
$final_item[0] = $key;
$final_item[1] = $item[1];
$final[] = $final_item;
}
else
{
$final[$found_index][1] .= ",".$item[1];
}
}
We create a new array $final, and loop through your old array $array_items. For each item, we see if there is already an item in $final that has the same [0] index. If it doesn't exist, we create it and add the initial string to the [1] index. If it does exist, we just have to add the string onto the end of the [1] index.
Try it, substituting $array_items for whatever your array is called, let me know if it works.
Check my solution. It should work fine. I hope it will help you much.
$result = $passed_keys = $extended_arr = [];
foreach ($arr as $k => $value) {
for($i = $k + 1; $i < count($arr); $i++){
if ( $value[0] == $arr[$i][0] ){ // compare each array with rest subsequent arrays
$key_name = $value[0];
if (!array_key_exists($key_name, $result)){
$result[$key_name] = $value[1] .",". $arr[$i][1];
} else {
if (!in_array($i, $passed_keys[$key_name])) {
$result[$key_name] .= ",". $arr[$i][1];
}
}
$passed_keys[$key_name][] = $i; // memorizing keys that were passed
}
}
}
array_walk($result, function($v, $k) use(&$extended_arr){
$extended_arr[] = [$k, $v];
});
The result is in $extended_arr
My solution, creates a custom key which makes identifying the letter much easier. This removes the need to continuously iterate through each array, which can become a major resources hog.
<?php
$inital_array = array(
array('A','XYZ'),
array('B','ABC'),
array('A','LMN'),
array('B','PQR')
);
$concat_array = array();
foreach($inital_array as $a){
$key = $a[0];
if( !isset($concat_array[$key]) ){
$concat_array[$key] = array($key,'');
}
$concat_array[$key][1] .= (empty($concat_array[$key][1]) ? '' : ',').$a[1];
}
$concat_array = array_values($concat_array);
echo '<pre>',print_r($concat_array),'</pre>';

Comparing 2 arrays and adding similar values

I have 2 arrays in PHP. One of them holds a list of dates, the other a list of numbers.
Array1
(
[0] => 2010-06-14
[1] => 2010-06-14
[2] => 2010-06-14
[3] => 2014-01-26
[4] => 2014-01-26
)
Array2
(
[0] => 120
[1] => 100
[2] => 60
[3] => 140
[4] => 30
)
The value [0] in Array2 belongs with the date [0] in Array1. What I am trying to do is add all of the values in Array2 together, based on the date. Any dates that match should have their values added together. So for example at the end I would like something like:
$date = 2010-06-14;
$value = 280;
$date = 2014-01-26;
$value = 170;
...and so on.
I've searched though the site but was unable to find exactly what I needed. Any help would be appreciated...
You can iterate $values, and get the corresponding date from $dates to use as the key in your result array.
foreach ($values as $key => $value) {
$result[$dates[$key]] = $value + ($result[$dates[$key]] ?? 0);
}
The output will be like this:
array (size=2)
'2010-06-14' => int 280
'2014-01-26' => int 170
$sum=0; // New Element
$Array3[][]=0; // New 2D array
$p=0; // Counter for 2D array
for($i=0;$i<5;$i++) // Single loop for traversing
{
$date=Array1[$i]; // Start for a date
while($date==Array1[$i]){ // For for Similar date
$sum=$sum+Array2[$i]; // Adding values of similar date
$i++; // Increment array
}
$Array3[$p]["date"]=$date; // Array3 date element
$Array3[$p]["sum"]=$sum; // Array4 date element
$i--; // Reducing a value which is incremented in while loop
}
Array3 is like
Array3
(
[0] => array( 'date' => " ",'sum' => " ")
[1] => array( 'date' => " ",'sum' => " ")
)
Are you trying to count all of the values in Array2 that have an entry in Array1 that matches some predefined target value?
If so, this for loop version should work:
private function forLoopVersion($array1, $array2, $target) {
$result = 0;
for ($i = 0; $i < count($array1); ++$i) {
if ($array1[$i] == $target) {
$result += $array2[$i];
}
}
return $result;
}
Also, this foreach loop version might work, but I do not know if the $key for $array1 can be used to index an element in $array2. You could try it:
private function foreachLoopVersion($array1, $array2, $target) {
$result = 0;
foreach ($array1 as $key => $value) {
if ($value == $target) {
$result += $array2[$key];
}
}
return $result;
}
$newArray = array();
for($i = 0; $i < count(Array1); $i++) {
$newArray[$Array1[$i]] = $Array2[$i];
}
echo $newArray[$date1] + $newArray[$date2];
Put the dates as keys to for easy math.

php multidimensional array from known key values

I have a collection of keys in this massive flat single array I would like to basically expand that array into a multidimensional one organized by keys - here is an example:
'invoice/products/data/item1'
'invoice/products/data/item2'
'invoice/products/data/item2'
=>
'invoice'=>'products'=>array('item1','item2','item3')
how can I do this - the length of the above strings are variable...
Thanks!
$src = array(
'invoice/products/data/item1',
'invoice/products/data/item2',
'invoice/products/data/item2',
'foo/bar/baz',
'aaa/bbb'
);
function rsplit(&$v, $w)
{
list($first, $tail) = explode('/', $w, 2);
if(empty($tail))
{
$v[] = $first;
return $v;
}
$v[$first] = rsplit($v[$first], $tail);
return $v;
}
$result = array_reduce($src, "rsplit");
print_r($result);
Output is:
Array (
[invoice] => Array
(
[products] => Array
(
[data] => Array
(
[0] => item1
[1] => item2
[2] => item2
)
)
)
[foo] => Array
(
[bar] => Array
(
[0] => baz
)
)
[aaa] => Array
(
[0] => bbb
)
)
Something along these lines: (Didn't test it though!) Works now ;)
$data = array();
$current = &$data;
foreach($keys as $value) {
$parts = explode("/", $value);
$parts_count = count($parts);
foreach($parts as $i => $part) {
if(!array_key_exists($part, $current)) {
if($i == $parts_count - 1) {
$current[] = $part;
}
else {
$current[$part] = array();
$current = &$current[$part];
}
}
else {
$current = &$current[$part];
}
}
$current = &$data;
}
$keys beeing the flat array.
Although it's not clear from your question how the "/" separated strings will map to an array, the basic approach will probably be something like this:
$result = array();
$k1 = $k2 = '';
ksort($yourData); // This is the key (!)
foreach ($yourData as $k => $v) {
// Use if / else if / else if to watch for new sub arrays and change
// $k1, $k2 accordingly
$result[$k1][$k2] = $v;
}
This approach uses the ksort to ensure that keys at the same "level" appear together, like this:
'invoice/products/data1/item1'
'invoice/products/data1/item2'
'invoice/products/data2/item3'
'invoice/products2/data3/item4'
'invoice/products2/data3/item5'
Notice how the ksort corresponds to the key grouping you're aiming for.

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