How can I delete duplicates in array?
For example if I had the following array:
$array = array('1','1','2','3');
I want it to become
$array = array('2','3');
so I want it to delete the whole value if two of it are found
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php.net/array_count_values <- I would try to write something with this function first. It counts at least how often one value has been used. Nicely keyed.hakre– hakre2013-05-04 08:49:15 +00:00Commented May 4, 2013 at 8:49
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Check out stackoverflow.com/questions/369602/…bestprogrammerintheworld– bestprogrammerintheworld2013-05-04 09:28:28 +00:00Commented May 4, 2013 at 9:28
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5 Answers
Depending on PHP version, this should work in all versions of PHP >= 4.0.6 as it doesn't require anonymous functions that require PHP >= 5.3:
function moreThanOne($val) {
return $val < 2;
}
$a1 = array('1','1','2','3');
print_r(array_keys(array_filter(array_count_values($a1), 'moreThanOne')));
DEMO (Change the PHP version in the drop-down to select the version of PHP you are using)
This works because:
array_count_valueswill go through the array and create an index for each value and increment it each time it encounters it again.array_filterwill take the created array and pass it through themoreThanOnefunction defined earlier, if it returnsfalse, the key/value pair will be removed.array_keyswill discard thevalueportion of the array creating an array with the values being the keys that were defined. This final step gives you a result that removes all values that existed more than once within the original array.
5 Comments
Ja͢ck
Anonymous functions were introduced in 5.3
Jon
Good point, so to modify the "not just PHP 5.4" it will be "for PHP > 4.0.6" ^^
Ja͢ck
It would work in 4.0.6 too, which is when
array_filter was introduced :)
bestprogrammerintheworld
+1 good usage of native php-functions. Well explained and a demo.
Jon
Grr @jack =P Lol, again, good point, maybe to tired to be creating version requirements for code. =]
You can filter them out using array_count_values():
$array = array('1','1','2','3');
$res = array_keys(array_filter(array_count_values($array), function($freq) {
return $freq == 1;
}));
The function returns an array comprising the original values and their respective frequencies; you then pick only the single frequencies. The end result is obtained by retrieving the keys.
Comments
Try this code,
<?php
$array = array('1','1','2','3');
foreach($array as $data){
$key= array_keys($array,$data);
if(count($key)>1){
foreach($key as $key2 => $data2){
unset($array[$key2]);
}
}
}
$array=array_values($array);
print_r($array);
?>
Output
Array ( [0] => 2 [1] => 3 )
Comments
PHP offers so many array functions, you just have to combine them:
$arr = array_keys(array_filter(array_count_values($arr), function($val) {
return $val === 1;
}));
Reference: array_keys, array_filter, array_count_values
Comments
Remove duplicate values from an array.
array_unique($array)
$array = array(4, "4", "3", 4, 3, "3");
$result = array_unique($array);
print_r($result);
/*
Array
(
[0] => 4
[2] => 3
)
*/
Comments
