How to find the duplicate and highest value in an array - php

I have an array like this
array={'a'=>'2','b'=>'5', 'c'=>'6', 'd'=>'6', 'e'=>'2'};
The array value might be different depending on the $_POST variables. My question is how to find the highest value in my array and return the index key. In my case, I need to get 'c' and 'd' and the value of 6. Not sure how to do this. Any helps would be appreciated. Thanks.

$max = max(array_values($array));
$keys = array_keys($array, $max);

Have a look at arsort which will sort an array in reverse order and maintain index association. So:
arsort($array);
This will end up with the largest values at the top of the array. Depending on what you need array_unique can remove duplicate values from your array.

$array = array(
'key1' => 22,
'key2' => 17,
'key3' => 19,
'key4' => 21,
'key5' => 24,
'key6' => 8,
);
function getHighest($array)
{
$highest = 0;
foreach($array as $index => $value)
{
if(is_numeric($value) && $value > $highest)
{
$highest = $index;
}
}
return $highest;
}
echo getHighest($array); //key5

Or this should do the magic, it would probably be faster than php built-in functions
$maxValue = -1;
$max = array();
foreach ($items as $key => $item) {
if ($item == $maxValue) {
$max[] = $key;
} elseif ($item > $maxValue) {
$max = array();
$max[] = $key;
$maxValue = $item;
}
}

Related

How do you append to an existing array in PHP after comparing with another array based on their keys?

Array1
(
[a]=>1; [b]=>2; [c]=>3
)
Array2
(
[a]=>1;[b] =>1
)
Required result:
Array1
(
[a]=>2; [b]=>3; [c]=>3
)
How do i append Array1 with the values of Array2 based on their key? Thanks.
You can try something like this:
foreach($array2 as $key2 => $val2){
if(key_exists($key2, $array1)) {
$array1[$key2] += $val2;
} else {
$array1[$key2] = $val2;
}
}
Part of the issue would be that array 1 may not have all of the same keys as array 2. So, an array of all keys from both original arrays is needed, then loop through those keys, check if it exists in either original array, and finally add it to the final combined array.
<?php
$array1 = array('a' => 1, 'b' => 2, 'c' => 3);
$array2 = array('a' => 1, 'b' => 2, 'd' => 3);
$finalarr = array();
$arrkeys = array_merge(array_keys($array1), array_keys($array2));
$arrkeys = array_unique($arrkeys);
foreach($arrkeys as $key) {
$finalarr[$key] = 0;
if (isset($array1[$key])) {
$finalarr[$key] += $array1[$key];
}
if (isset($array2[$key])) {
$finalarr[$key] += $array2[$key];
}
}
print_r($finalarr);
?>
foreach($array1 as $key=>$value){
if(isset($array2[$key])){
$array1[$key] = $array1[$key] + $array2[$key];
}
}
Not the most elegant way, which would use array_walk or array_map, but I like to see and know exactly what's going on. This will give you what you are looking for.
First sum the values of the common keys and after that, add the others key in the other array:
foreach ($array2 as $k2 => $a2){
if (isset($array1[$k2])){
$array1[$k2]+=$a2;
unset($array2[$k2]);
}
}
$array1 += $array2;
Something like:
$result = array();
function ParseArray(array $array, array &$result)
{
foreach ($array as $k => $v) {
if (!array_key_exists($k, $result) {
$result[$k] = $v;
} else {
$result[$k] += $v;
}
}
}
ParseArray($Array1, $result);
ParseArray($Array2, $result);
print_r($result);
You should read about PHP array functions.
$array1 = array(
'a' => 1,
'b' => 2,
'c' => 3,
);
$array2 = array(
'a' => 1,
'b' => 1,
);
array_walk(
$array1,
function (&$value, $key) use ($array2) {
$value += (isset($array2[$key])) ? $array2[$key] : 0;
}
);
var_dump($array1);

Checking during array iteration, if the current element is the last element

Please help me to translate this pseudo-code to real php code:
foreach ($arr as $k => $v)
if ( THIS IS NOT THE LAST ELEMENT IN THE ARRAY)
doSomething();
Edit: the array may have numerical or string keys
you can use PHP's end()
$array = array('a' => 1,'b' => 2,'c' => 3);
$lastElement = end($array);
foreach($array as $k => $v) {
echo $v . '<br/>';
if($v == $lastElement) {
// 'you can do something here as this condition states it just entered last element of an array';
}
}
Update1
as pointed out by #Mijoja the above could will have problem if you have same value multiple times in array. below is the fix for it.
$array = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 2);
//point to end of the array
end($array);
//fetch key of the last element of the array.
$lastElementKey = key($array);
//iterate the array
foreach($array as $k => $v) {
if($k == $lastElementKey) {
//during array iteration this condition states the last element.
}
}
Update2
I found solution by #onteria_ to be better then what i have answered since it does not modify arrays internal pointer, i am updating the answer to match his answer.
$array = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 2);
// Get array keys
$arrayKeys = array_keys($array);
// Fetch last array key
$lastArrayKey = array_pop($arrayKeys);
//iterate array
foreach($array as $k => $v) {
if($k == $lastArrayKey) {
//during array iteration this condition states the last element.
}
}
Thank you #onteria_
Update3
As pointed by #CGundlach PHP 7.3 introduced array_key_last which seems much better option if you are using PHP >= 7.3
$array = array('a' => 1,'b' => 2,'c' => 3);
$lastKey = array_key_last($array);
foreach($array as $k => $v) {
echo $v . '<br/>';
if($k == $lastKey) {
// 'you can do something here as this condition states it just entered last element of an array';
}
}
This always does the trick for me
foreach($array as $key => $value) {
if (end(array_keys($array)) == $key)
// Last key reached
}
Edit 30/04/15
$last_key = end(array_keys($array));
reset($array);
foreach($array as $key => $value) {
if ( $key == $last_key)
// Last key reached
}
To avoid the E_STRICT warning mentioned by #Warren Sergent
$array_keys = array_keys($array);
$last_key = end($array_keys);
$myarray = array(
'test1' => 'foo',
'test2' => 'bar',
'test3' => 'baz',
'test4' => 'waldo'
);
$myarray2 = array(
'foo',
'bar',
'baz',
'waldo'
);
// Get the last array_key
$last = array_pop(array_keys($myarray));
foreach($myarray as $key => $value) {
if($key != $last) {
echo "$key -> $value\n";
}
}
// Get the last array_key
$last = array_pop(array_keys($myarray2));
foreach($myarray2 as $key => $value) {
if($key != $last) {
echo "$key -> $value\n";
}
}
Since array_pop works on the temporary array created by array_keys it doesn't modify the original array at all.
$ php test.php
test1 -> foo
test2 -> bar
test3 -> baz
0 -> foo
1 -> bar
2 -> baz
Why not this very simple method:
$i = 0; //a counter to track which element we are at
foreach($array as $index => $value) {
$i++;
if( $i == sizeof($array) ){
//we are at the last element of the array
}
}
I know this is old, and using SPL iterator maybe just an overkill, but anyway, another solution here:
$ary = array(1, 2, 3, 4, 'last');
$ary = new ArrayIterator($ary);
$ary = new CachingIterator($ary);
foreach ($ary as $each) {
if (!$ary->hasNext()) { // we chain ArrayIterator and CachingIterator
// just to use this `hasNext()` method to see
// if this is the last element
echo $each;
}
}
My solution, also quite simple..
$array = [...];
$last = count($array) - 1;
foreach($array as $index => $value)
{
if($index == $last)
// this is last array
else
// this is not last array
}
If the items are numerically ordered, use the key() function to determine the index of the current item and compare it to the length. You'd have to use next() or prev() to cycle through items in a while loop instead of a for loop:
$length = sizeOf($arr);
while (key(current($arr)) != $length-1) {
$v = current($arr); doSomething($v); //do something if not the last item
next($myArray); //set pointer to next item
}
Simple approach using array_keys function to get the keys and get only first key [0] of reversed array which is the last key.
$array = array('a' => 1,'b' => 2,'c' => 3);
$last_key = array_keys(array_reverse($array, true))[0];
foreach($array as $key => $value) {
if ($last_key !== $key)
// THIS IS NOT THE LAST ELEMENT IN THE ARRAY doSomething();
}
NOTE: array_reverse reverse array take two arguments first array we want be reversed and second parameter true, to reverse the array and preserves the order of keys.

How to count the consecutive duplicate values in an array?

I have an array like this:
$arr = array(1, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3);
I found the function array_count_values(), but it will group all of the same values and count the occurrences without respecting breaks in the consecutive sequences.
$result[1] = 5
$result[2] = 4
$result[3] = 3
How can I group each set of consecutive values and count the length of each sequence? Notice there are two sets of sequences for the numbers 1, 2, and 3.
The data that I expect to generate needs to resemble this:
[1] = 3;
[2] = 2;
[3] = 2;
[1] = 2;
[2] = 2;
[3] = 1;
It can be done simply manually:
$arr = array(1,1,1,2,2,3,3,1,1,2,2,3);
$result = array();
$prev_value = array('value' => null, 'amount' => null);
foreach ($arr as $val) {
if ($prev_value['value'] != $val) {
unset($prev_value);
$prev_value = array('value' => $val, 'amount' => 0);
$result[] =& $prev_value;
}
$prev_value['amount']++;
}
var_dump($result);
My suggestion is to extract&remove the first value from the array prior to entering the loop and use a temporary array ($carry) to track whether each new value matches the key in the carry array. If so, increment it. If not, push the completed sequence count into the result array and overwrite the carry with the new value and set the counter to 1. When the loop finishes, push the lingering carry into the result set. My snippet does not check if the input array is empty; if necessary, add that condition to your project.
Code: (Demo)
$array = [1,1,1,2,2,3,3,1,1,2,2,3];
$result = [];
$carry = [array_shift($array) => 1];
foreach ($array as $value) {
if (isset($carry[$value])) {
++$carry[$value];
} else {
$result[] = $carry;
$carry = [$value => 1];
}
}
$result[] = $carry;
print_r($result);
Output: (condensed to reduce page bloat)
[
[1 => 3],
[2 => 2],
[3 => 2],
[1 => 2],
[2 => 2],
[3 => 1],
]
If you'd rather implement a zerkms-style, modify-by-reference style technique, the following snippet provides the same result as the above snippet.
Effectively, it pushes every newly encountered value as an associative, single-element array into the indexed result array. Because the pushed subarray is declared as a variable ($carry) then assigned-by-reference (= &) to the result array, incrementation of $carry will be applied to the deeply nested value in the result array. The output array requires the additional depth in its structure so that a given value which occurs multiple times can be reliably stored.
Code: (Demo)
$result = [];
$carry = [];
foreach ($array as $value) {
if ($carry && key($carry) === $value) {
++$carry[$value];
} else {
unset($carry);
$carry = [$value => 1];
$result[] = &$carry;
}
}
unset($carry);
print_r($result);
Unsetting the reference variable $carry after the loop may not be necessary, but if there is any potential re-use of that variable within the variable's scope, it will be important to uncouple the reference with unset().
And just for fun, here is a hideous regex-infused approach that works with the sample data: Demo
What about PHP's array_count_values function?
<?php
$array = array(1, "hello", 1, "world", "hello");
print_r(array_count_values($array));
?>
output:
Array
(
[1] => 2
[hello] => 2
[world] => 1
)
function findRepetitions($times, $array) {
$values = array_unique($array);
$counts = [];
foreach($values as $value) {
$counts[] = ['value' => $value, 'count' => 0];
}
foreach ($array as $value) {
foreach ($counts as $key => $count) {
if ($count['value'] === $value) {
$counts[$key]['count']++;
}
}
}
$repetitions = [];
foreach ($counts as $count) {
if ($count['count'] === $times) {
$repetitions[] = $count['value'];
}
}
return $repetitions;
}
$current = null;
foreach($your_array as $v) {
if($v == $current) {
$result[count($result)-1]++;
} else {
$result[] = 1;
$current = $v;
}
}
var_dump($result);
Here is the way that I would do it:
function SplitIntoGroups($array)
{
$toReturnArray = array();
$currentNumber = $array[0];
$currentCount = 1;
for($i=1; $i <= count($array); $i++)
{
if($array[$i] == $currentNumber)
{
$currentCount++;
}
else
{
$toReturnArray[] = array($currentNumber, $currentCount);
$currentNumber = $array[$i];
$currentCount = 1;
}
}
return $toReturnArray;
}
$answer = SplitIntoGroups(array(1,1,1,2,2,3,3,1,1,2,2,3));
for($i=0; $i<count($answer); $i++)
{
echo '[' . $answer[$i][0] . '] = ' . $answer[$i][1] . '<br />';
}

Switch two items in associative array

Example:
$arr = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
I want to switch the positions of grapefruit and pear, so the array will become
$arr = array(
'apple' => 'sweet',
'pear' => 'tasty',
'grapefruit' => 'bitter',
'banana' => 'yellow'
)
I know the keys and values of the elements I want to switch, is there an easy way to do this? Or will it require a loop + creating a new array?
Thanks
Just a little shorter and less complicated than the solution of arcaneerudite:
<?php
if(!function_exists('array_swap_assoc')) {
function array_swap_assoc($key1, $key2, $array) {
$newArray = array ();
foreach ($array as $key => $value) {
if ($key == $key1) {
$newArray[$key2] = $array[$key2];
} elseif ($key == $key2) {
$newArray[$key1] = $array[$key1];
} else {
$newArray[$key] = $value;
}
}
return $newArray;
}
}
$array = $arrOrig = array(
'fruit' => 'pear',
'veg' => 'cucumber',
'tuber' => 'potato',
'meat' => 'ham'
);
$newArray = array_swap_assoc('veg', 'tuber', $array);
var_dump($array, $newArray);
?>
Tested and works fine
Here's my version of the swap function:
function array_swap_assoc(&$array,$k1,$k2) {
if($k1 === $k2) return; // Nothing to do
$keys = array_keys($array);
$p1 = array_search($k1, $keys);
if($p1 === FALSE) return; // Sanity check...keys must exist
$p2 = array_search($k2, $keys);
if($p2 === FALSE) return;
$keys[$p1] = $k2; // Swap the keys
$keys[$p2] = $k1;
$values = array_values($array);
// Swap the values
list($values[$p1],$values[$p2]) = array($values[$p2],$values[$p1]);
$array = array_combine($keys, $values);
}
if the array comes from the db, add a sort_order field so you can always be sure in what order the elements are in the array.
This may or may not be an option depending on your particular use-case, but if you initialize your array with null values with the appropriate keys before populating it with data, you can set the values in any order and the original key-order will be maintained. So instead of swapping elements, you can prevent the need to swap them entirely:
$arr = array('apple' => null,
'pear' => null,
'grapefruit' => null,
'banana' => null);
...
$arr['apple'] = 'sweet';
$arr['grapefruit'] = 'bitter'; // set grapefruit before setting pear
$arr['pear'] = 'tasty';
$arr['banana'] = 'yellow';
print_r($arr);
>>> Array
(
[apple] => sweet
[pear] => tasty
[grapefruit] => bitter
[banana] => yellow
)
Not entirely sure if this was mentioned, but, the reason this is tricky is because it's non-indexed.
Let's take:
$arrOrig = array(
'fruit'=>'pear',
'veg'=>'cucumber',
'tuber'=>'potato'
);
Get the keys:
$arrKeys = array_keys($arrOrig);
print_r($arrKeys);
Array(
[0]=>fruit
[1]=>veg
[2]=>tuber
)
Get the values:
$arrVals = array_values($arrOrig);
print_r($arrVals);
Array(
[0]=>pear
[1]=>cucumber
[2]=>potato
)
Now you've got 2 arrays that are numerical. Swap the indices of the ones you want to swap, then read the other array back in in the order of the modified numerical array. Let's say we want to swap 'fruit' and 'veg':
$arrKeysFlipped = array_flip($arrKeys);
print_r($arrKeysFlipped);
Array (
[fruit]=>0
[veg]=>1
[tuber]=>2
)
$indexFruit = $arrKeysFlipped['fruit'];
$indexVeg = $arrKeysFlipped['veg'];
$arrKeysFlipped['veg'] = $indexFruit;
$arrKeysFlipped['fruit'] = $indexVeg;
print_r($arrKeysFlipped);
Array (
[fruit]=>1
[veg]=>0
[tuber]=>2
)
Now, you can swap back the array:
$arrKeys = array_flip($arrKeysFlipped);
print_r($arrKeys);
Array (
[0]=>veg
[1]=>fruit
[2]=>tuber
)
Now, you can build an array by going through the oringal array in the 'order' of the rearranged keys.
$arrNew = array ();
foreach($arrKeys as $index=>$key) {
$arrNew[$key] = $arrOrig[$key];
}
print_r($arrNew);
Array (
[veg]=>cucumber
[fruit]=>pear
[tuber]=>potato
)
I haven't tested this - but this is what I'd expect. Does this at least provide any kind of help? Good luck :)
You could put this into a function $arrNew = array_swap_assoc($key1,$key2,$arrOld);
<?php
if(!function_exists('array_swap_assoc')) {
function array_swap_assoc($key1='',$key2='',$arrOld=array()) {
$arrNew = array ();
if(is_array($arrOld) && count($arrOld) > 0) {
$arrKeys = array_keys($arrOld);
$arrFlip = array_flip($arrKeys);
$indexA = $arrFlip[$key1];
$indexB = $arrFlip[$key2];
$arrFlip[$key1]=$indexB;
$arrFlip[$key2]=$indexA;
$arrKeys = array_flip($arrFlip);
foreach($arrKeys as $index=>$key) {
$arrNew[$key] = $arrOld[$key];
}
} else {
$arrNew = $arrOld;
}
return $arrNew;
}
}
?>
WARNING: Please test and debug this before just using it - no testing has been done at all.
There is no easy way, just a loop or a new array definition.
Classical associative array doesn't define or guarantee sequence of elements in any way. There is plain array/vector for that. If you use associative array you are assumed to need random access but not sequential. For me you are using assoc array for task it is not made for.
yeah I agree with Lex, if you are using an associative array to hold data, why not using your logic handle how they are accessed instead of depending on how they are arranged in the array.
If you really wanted to make sure they were in a correct order, trying creating fruit objects and then put them in a normal array.
There is no easy way to do this. This sounds like a slight design-logic error on your part which has lead you to try to do this when there is a better way to do whatever it is you are wanting to do. Can you tell us why you want to do this?
You say that I know the keys and values of the elements I want to switch which makes me think that what you really want is a sorting function since you can easily access the proper elements anytime you want as they are.
$value = $array[$key];
If that is the case then I would use sort(), ksort() or one of the many other sorting functions to get the array how you want. You can even use usort() to Sort an array by values using a user-defined comparison function.
Other than that you can use array_replace() if you ever need to swap values or keys.
Here are two solutions. The first is longer, but doesn't create a temporary array, so it saves memory. The second probably runs faster, but uses more memory:
function swap1(array &$a, $key1, $key2)
{
if (!array_key_exists($key1, $a) || !array_key_exists($key2, $a) || $key1 == $key2) return false;
$after = array();
while (list($key, $val) = each($a))
{
if ($key1 == $key)
{
break;
}
else if ($key2 == $key)
{
$tmp = $key1;
$key1 = $key2;
$key2 = $tmp;
break;
}
}
$val1 = $a[$key1];
$val2 = $a[$key2];
while (list($key, $val) = each($a))
{
if ($key == $key2)
$after[$key1] = $val1;
else
$after[$key] = $val;
unset($a[$key]);
}
unset($a[$key1]);
$a[$key2] = $val2;
while (list($key, $val) = each($after))
{
$a[$key] = $val;
unset($after[$key]);
}
return true;
}
function swap2(array &$a, $key1, $key2)
{
if (!array_key_exists($key1, $a) || !array_key_exists($key2, $a) || $key1 == $key2) return false;
$swapped = array();
foreach ($a as $key => $val)
{
if ($key == $key1)
$swapped[$key2] = $a[$key2];
else if ($key == $key2)
$swapped[$key1] = $a[$key1];
else
$swapped[$key] = $val;
}
$a = $swapped;
return true;
}
fwiw here is a function to swap two adjacent items to implement moveUp() or moveDown() in an associative array without foreach()
/**
* #param array $array to modify
* #param string $key key to move
* #param int $direction +1 for down | -1 for up
* #return $array
*/
protected function moveInArray($array, $key, $direction = 1)
{
if (empty($array)) {
return $array;
}
$keys = array_keys($array);
$index = array_search($key, $keys);
if ($index === false) {
return $array; // not found
}
if ($direction < 0) {
$index--;
}
if ($index < 0 || $index >= count($array) - 1) {
return $array; // at the edge: cannot move
}
$a = $keys[$index];
$b = $keys[$index + 1];
$result = array_slice($array, 0, $index, true);
$result[$b] = $array[$b];
$result[$a] = $array[$a];
return array_merge($result, array_slice($array, $index + 2, null, true));
}
There is an easy way:
$sourceArray = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
// set new order
$orderArray = array(
'apple' => '', //this values would be replaced
'pear' => '',
'grapefruit' => '',
//it is not necessary to touch all elemets that will remains the same
);
$result = array_replace($orderArray, $sourceArray);
print_r($result);
and you get:
$result = array(
'apple' => 'sweet',
'pear' => 'tasty',
'grapefruit' => 'bitter',
'banana' => 'yellow'
)
function arr_swap_keys(array &$arr, $key1, $key2, $f_swap_vals=false) {
// if f_swap_vals is false, then
// swap only the keys, keeping the original values in their original place
// ( i.e. do not preserve the key value correspondence )
// i.e. if arr is (originally)
// [ 'dog' => 'alpha', 'cat' => 'beta', 'horse' => 'gamma' ]
// then calling this on arr with, e.g. key1 = 'cat', and key2 = 'horse'
// will result in arr becoming:
// [ 'dog' => 'alpha', 'horse' => 'beta', 'cat' => 'gamma' ]
//
// if f_swap_vals is true, then preserve the key value correspondence
// i.e. in the above example, arr will become:
// [ 'dog' => 'alpha', 'horse' => 'gamma', 'cat' => 'beta' ]
//
//
$arr_vals = array_values($arr); // is a (numerical) index to value mapping
$arr_keys = array_keys($arr); // is a (numerical) index to key mapping
$arr_key2idx = array_flip($arr_keys);
$idx1 = $arr_key2idx[$key1];
$idx2 = $arr_key2idx[$key2];
swap($arr_keys[$idx1], $arr_keys[$idx2]);
if ( $f_swap_vals ) {
swap($arr_vals[$idx1], $arr_vals[$idx2]);
}
$arr = array_combine($arr_keys, $arr_vals);
}
function swap(&$a, &$b) {
$t = $a;
$a = $b;
$b = $t;
}
Well it's just a key sorting problem. We can use uksort for this purpose. It needs a key comparison function and we only need to know that it should return 0 to leave keys position untouched and something other than 0 to move key up or down.
Notice that it will only work if your keys you want to swap are next to each other.
<?php
$arr = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
uksort(
$arr,
function ($k1, $k2) {
if ($k1 == 'grapefruit' && $k2 == 'pear') return 1;
else return 0;
}
);
var_dump($arr);
I'll share my short version too, it works with both numeric and associative arrays.
array array_swap ( array $array , mixed $key1 , mixed $key2 [, bool $preserve_keys = FALSE [, bool $strict = FALSE ]] )
Returns a new array with the two elements swapped. It preserve original keys if specified. Return FALSE if keys are not found.
function array_swap(array $array, $key1, $key2, $preserve_keys = false, $strict = false) {
$keys = array_keys($array);
if(!array_key_exists($key1, $array) || !array_key_exists($key2, $array)) return false;
if(($index1 = array_search($key1, $keys, $strict)) === false) return false;
if(($index2 = array_search($key2, $keys, $strict)) === false) return false;
if(!$preserve_keys) list($keys[$index1], $keys[$index2]) = array($key2, $key1);
list($array[$key1], $array[$key2]) = array($array[$key2], $array[$key1]);
return array_combine($keys, array_values($array));
}
For example:
$arr = array_swap($arr, 'grapefruit', 'pear');
I wrote a function with more general purpose, with this problem in mind.
array with known keys
specify order of keys in a second array ($order array keys indicate key position)
function order_array($array, $order) {
foreach (array_keys($array) as $k => $v) {
$keys[++$k] = $v;
}
for ($i = 1; $i <= count($array); $i++) {
if (isset($order[$i])) {
unset($keys[array_search($order[$i], $keys)]);
}
if ($i === count($array)) {
array_push($keys, $order[$i]);
} else {
array_splice($keys, $i-1, 0, $order[$i]);
}
}
}
foreach ($keys as $key) {
$result[$key] = $array[$key];
}
return $result;
} else {
return false;
}
}
$order = array(1 => 'item3', 2 => 'item5');
$array = array("item1" => 'val1', "item2" => 'val2', "item3" => 'val3', "item4" => 'val4', "item5" => 'val5');
print_r($array); -> Array ( [item1] => val1 [item2] => val2 [item3] => val3 [item4] => val4 [item5] => val5 )
print_r(order_array($array, $order)); -> Array ( [item3] => val3 [item5] => val5 [item1] => val1 [item2] => val2 [item4] => val4 )
I hope this is relevant / helpful for someone
Arrays in php are ordered maps.
$arr = array('apple'=>'sweet','grapefruit'=>'bitter','
pear'=>'tasty','banana'=>'yellow');
doesn't mean that that the first element is 'apple'=>'sweet' and the last - 'banana'=>'yellow' just because you put 'apple' first and 'banana' last. Actually, 'apple'=>'sweet' will be the first and
'banana'=>'yellow' will be the second because of alphabetical ascending sort order.

How to remove duplicate values from an array in PHP

How can I remove duplicate values from an array in PHP?
Use array_unique().
Example:
$array = array(1, 2, 2, 3);
$array = array_unique($array); // Array is now (1, 2, 3)
Use array_values(array_unique($array));
array_unique: for unique array
array_values: for reindexing
//Find duplicates
$arr = array(
'unique',
'duplicate',
'distinct',
'justone',
'three3',
'duplicate',
'three3',
'three3',
'onlyone'
);
$unique = array_unique($arr);
$dupes = array_diff_key( $arr, $unique );
// array( 5=>'duplicate', 6=>'three3' 7=>'three3' )
// count duplicates
array_count_values($dupes); // array( 'duplicate'=>1, 'three3'=>2 )
$result = array();
foreach ($array as $key => $value){
if(!in_array($value, $result))
$result[$key]=$value;
}
The only thing which worked for me is:
$array = array_unique($array, SORT_REGULAR);
Edit : SORT_REGULAR keeps the same order of the original array.
sometimes array_unique() is not the way,
if you want get unique AND duplicated items...
$unique=array("","A1","","A2","","A1","");
$duplicated=array();
foreach($unique as $k=>$v) {
if( ($kt=array_search($v,$unique))!==false and $k!=$kt )
{ unset($unique[$kt]); $duplicated[]=$v; }
}
sort($unique); // optional
sort($duplicated); // optional
results on
array ( 0 => '', 1 => 'A1', 2 => 'A2', ) /* $unique */
array ( 0 => '', 1 => '', 2 => '', 3 => 'A1', ) /* $duplicated */
We can easily use arrar_unique($array); to remove duplicate elements
But the problem in this method is that the index of the elements are not in order, will cause problems if used somewhere else later.
Use
$arr = array_unique($arr);
$arr = array_values($arr);
print_r($arr);
Or
$arr = array_flip($arr);
$arr = array_flip($arr);
$arr = array_values($arr);
print_r($arr);
The first flip , flips the key value pair thus combines the elements with similar key(that was originally the value).
2nd flip to revert all the key value pairs. Finally array_value() sets each value with key starting from 0.
Note: Not to be used in associative array with predefined key value pairs
$a = array(1, 2, 3, 4);
$b = array(1, 6, 5, 2, 9);
$c = array_merge($a, $b);
$unique = array_keys(array_flip($c));
print_r($unique);
We can create such type of array to use this last value will be updated into column or key value and we will get unique value from the array...
$array = array (1,3,4,2,1,7,4,9,7,5,9);
$data=array();
foreach($array as $value ){
$data[$value]= $value;
}
array_keys($data);
OR
array_values($data);
explode(",", implode(",", array_unique(explode(",", $YOUR_ARRAY))));
This will take care of key associations and serialize the keys for the resulting new array :-)
Depending on the size of your array, I have found
$array = array_values( array_flip( array_flip( $array ) ) );
can be faster than array_unique.
There can be multiple ways to do these, which are as follows
//first method
$filter = array_map("unserialize", array_unique(array_map("serialize", $arr)));
//second method
$array = array_unique($arr, SORT_REGULAR);
If you concern in performance and have simple array, use:
array_keys(array_flip($array));
It's many times faster than array_unique.
This example is just an alternative.
<?php
$numbers = [1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,65776567567,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1,1,3,4,5,6,2,5,7,1];
$unique_numbers = [];
foreach($numbers as $number)
{
if(!in_array($number,$unique_numbers)){
$unique_numbers[] = $number;
}
}
print(json_encode($unique_numbers)); //// Array is now 1,3,4,5,6,2,7, ....
That's a great way to do it. Might want to make sure its output is back an array again. Now you're only showing the last unique value.
Try this:
$arrDuplicate = array ("","",1,3,"",5);
foreach (array_unique($arrDuplicate) as $v){
if($v != "") { $arrRemoved[] = $v; }
}
print_r ($arrRemoved);
if (#!in_array($classified->category,$arr)){
$arr[] = $classified->category;
?>
<?php } endwhile; wp_reset_query(); ?>
first time check value in array and found same value ignore it
Remove duplicate values from an associative array in PHP.
$arrDup = Array ('0' => 'aaa-aaa' , 'SKU' => 'aaa-aaa' , '1' => '12/1/1' , 'date' => '12/1/1' , '2' => '1.15' , 'cost' => '1.15' );
foreach($arrDup as $k => $v){
if(!( isset ($hold[$v])))
$hold[$v]=1;
else
unset($arrDup[$k]);
}
Array ( [0] => aaa-aaa [1] => 12/1/1 [2] => 1.15 )
$arrDuplicate = array ("","",1,3,"",5);
foreach(array_unique($arrDuplicate) as $v){
if($v != "" ){$arrRemoved = $v; }}
print_r($arrRemoved);
try this short & sweet code -
$array = array (1,4,2,1,7,4,9,7,5,9);
$unique = array();
foreach($array as $v){
isset($k[$v]) || ($k[$v]=1) && $unique[] = $v;
}
var_dump($unique);
Output -
array(6) {
[0]=>
int(1)
[1]=>
int(4)
[2]=>
int(2)
[3]=>
int(7)
[4]=>
int(9)
[5]=>
int(5)
}
<?php
$arr1 = [1,1,2,3,4,5,6,3,1,3,5,3,20];
print_r(arr_unique($arr1));
function arr_unique($arr) {
sort($arr);
$curr = $arr[0];
$uni_arr[] = $arr[0];
for($i=0; $i<count($arr);$i++){
if($curr != $arr[$i]) {
$uni_arr[] = $arr[$i];
$curr = $arr[$i];
}
}
return $uni_arr;
}
Here I've created a second empty array and used for loop with the first array which is having duplicates. It will run as many time as the count of the first array. Then compared with the position of the array with the first array and matched that it has this item already or not by using in_array. If not then it'll add that item to second array with array_push.
$a = array(1,2,3,1,3,4,5);
$count = count($a);
$b = [];
for($i=0; $i<$count; $i++){
if(!in_array($a[$i], $b)){
array_push($b, $a[$i]);
}
}
print_r ($b);
It can be done through function I made three function duplicate returns the values which are duplicate in array.
Second function single return only those values which are single mean not repeated in array and third and full function return all values but not duplicated if any value is duplicated it convert it to single;
function duplicate($arr) {
$duplicate;
$count = array_count_values($arr);
foreach($arr as $key => $value) {
if ($count[$value] > 1) {
$duplicate[$value] = $value;
}
}
return $duplicate;
}
function single($arr) {
$single;
$count = array_count_values($arr);
foreach($arr as $key => $value) {
if ($count[$value] == 1) {
$single[$value] = $value;
}
}
return $single;
}
function full($arr, $arry) {
$full = $arr + $arry;
sort($full);
return $full;
}
As an alternative of array_unique() you may use php Set class
$array = array(1, 2, 2, 3);
$array = (new \Ds\Set($array))->toArray() ; // Array is now (1, 2, 3)
An alternative for array_unique() function..
Using Brute force algorithm
//[1] This our array with duplicated items
$matches = ["jorge","melvin","chelsy","melvin","jorge","smith"];
//[2] Container for the new array without any duplicated items
$arr = [];
//[3] get the length of the duplicated array and set it to the var len to be use for for loop
$len = count($matches);
//[4] If matches array key($i) current loop Iteration is not available in
//[4] the array $arr then push the current iteration key value of the matches[$i]
//[4] to the array arr.
for($i=0;$i
if(array_search($matches[$i], $arr) === false){
array_push($arr,$matches[$i]);
}
}
//print the array $arr.
print_r($arr);
//Result: Array
(
[0] => jorge
[1] => melvin
[2] => chelsy
[3] => smith
)
<?php
$a=array("1"=>"302","2"=>"302","3"=>"276","4"=>"301","5"=>"302");
print_r(array_values(array_unique($a)));
?>//`output -> Array ( [0] => 302 [1] => 276 [2] => 301 )`
I have done this without using any function.
$arr = array("1", "2", "3", "4", "5", "4", "2", "1");
$len = count($arr);
for ($i = 0; $i < $len; $i++) {
$temp = $arr[$i];
$j = $i;
for ($k = 0; $k < $len; $k++) {
if ($k != $j) {
if ($temp == $arr[$k]) {
echo $temp."<br>";
$arr[$k]=" ";
}
}
}
}
for ($i = 0; $i < $len; $i++) {
echo $arr[$i] . " <br><br>";
}
$array = array("a" => "moon", "star", "b" => "moon", "star", "sky");
// Deleting the duplicate items
$result = array_unique($array);
print_r($result);
ref : Demo

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