array_count_values

(PHP 4, PHP 5)

array_count_values — Zählt die Werte eines Arrays

Beschreibung

array array_count_values ( array $array )

array_count_values() gibt ein Array zurück, in dem die Werte des Arrays array als Schlüssel, und die Häufigkeit ihres Auftretens als Werte angegeben sind.

Parameter-Liste

array: Das Array mit den zu zählenden Werten

Rückgabewerte

Gibt ein assoziatives Array mit den Werten aus array als Schlüsseln und der Anzahl als Werten zurück.

Fehler/Exceptions

Erzeugt ein E_WARNING für jedes Element, welches kein string oder integer ist.

Beispiele

Beispiel #1 array_count_values()-Beispiel


<?php
$array = array(1, "hello", 1, "world", "hello");
print_r(array_count_values($array));
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

Array
(
    [1] => 2
    [hello] => 2
    [world] => 1
)

Siehe auch

count() - Zählt alle Elemente eines Arrays oder Attribute eines Objekts
array_unique() - Entfernt doppelte Werte aus einem Array
array_values() - Liefert alle Werte eines Arrays
count_chars() - Gibt Informationen über die in einem String enthaltenen Zeichen zurück

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User Contributed Notes 11 notes

down

[Mr.A] ¶

9 years ago


I find a very simple solution to count values in multidimentional arrays (example for 2 levels) :

foreach ($array as $a) {
  foreach ($a as $b) {
    $count_values[$b]++;
  }
}

down

jakubplus at gmail dot com ¶

10 months ago


In order to apply array_map with callback checking for localised values like city name, country name, you have to provide some sort of comparison array.

Here's an example of array_count_values for Polish city names. Just switch array_keys / array_values in order to obtain lowercase / uppercase.

$arr = array('Warsaw', 'Warsaw', 'Wrocław', 'Poznań', 'KrakÓw', 'waRsaw', 'Gdańsk', 'poznań', 'WROCŁAW', 'kraków', 'GDAŃSK');
$lowertoupperpolish = array(
    'ą' => 'Ą',
    'ć' => 'Ć',
    'ę' => 'Ę',
    'ł' => 'Ł',
    'ń' => 'Ń',
    'ó' => 'Ó',
    'ś' => 'Ś',
    'ż' => 'Ż',
    'ź' => 'Ź',
);
function lowers($n) {
    global $lowertoupperpolish;
    return strtolower(str_replace(array_values($lowertoupperpolish), array_keys($lowertoupperpolish), $n));
}
$result = array_count_values(array_map('lowers', $arr));

print_r($result); ...prints:

Array ( [warsaw] => 3 [wrocław] => 2 [poznań] => 2 [kraków] => 2 [gdańsk] => 2 )

down

majerm at gmail dot com ¶

7 years ago


<?
function array_icount_values($array) {
    $ret_array = array();
    foreach($array as $value) $ret_array[strtolower($value)]++;
    return $ret_array;
}

$ar = array('J. Karjalainen', 'J. Karjalainen', 60, '60', 'J. Karjalainen', 'j. karjalainen', 'Fastway', 'FASTWAY', 'Fastway', 'fastway', 'YUP');
$ar = array_icount_values($ar);
?>

this prints:

Array
(
    [j. karjalainen] => 4
    [60] => 2
    [fastway] => 4
    [yup] => 1
)

down

Hayley Watson ¶

6 years ago


Yet Another case-insensitive version of array_count_values()

<?php
$ar = array('J. Karjalainen', 'J. Karjalainen', 60, '60', 'J. Karjalainen', 'j. karjalainen', 'Fastway', 'FASTWAY', 'Fastway', 'fastway', 'YUP');

$ar = array_count_values(array_map('strtolower', $ar));
?>

down

Dominic Vonk ¶

1 year ago


The case-insensitive version:

<?php
function array_count_values_ci($array) {
    $newArray = array();
    foreach ($array as $values) {
        if (!array_key_exists(strtolower($values), $newArray)) {
            $newArray[strtolower($values)] = 0;
        }
        $newArray[strtolower($values)] += 1;
    }
    return $newArray;
}
?>

down

rabies dot dostojevski at gmail dot com ¶

7 years ago


I couldn't find a function for counting the values with case-insensitive matching, so I wrote a quick and dirty solution myself:

<pre><?php
function array_icount_values($array) {
    $ret_array = array();
    foreach($array as $value) {
        foreach($ret_array as $key2 => $value2) {
            if(strtolower($key2) == strtolower($value)) {
                $ret_array[$key2]++;
                continue 2;
            }
        }
        $ret_array[$value] = 1;
    }
    return $ret_array;
}

$ar = array('J. Karjalainen', 'J. Karjalainen', 60, '60', 'J. Karjalainen', 'j. karjalainen', 'Fastway', 'FASTWAY', 'Fastway', 'fastway', 'YUP');
$ar2 = array_count_values($ar); // Normal matching
$ar = array_icount_values($ar); // Case-insensitive matching
print_r($ar2);
print_r($ar);
?></pre>

This prints:

Array
(
    [J. Karjalainen] => 3
    [60] => 2
    [j. karjalainen] => 1
    [Fastway] => 2
    [FASTWAY] => 1
    [fastway] => 1
    [YUP] => 1
)
Array
(
    [J. Karjalainen] => 4
    [60] => 2
    [Fastway] => 4
    [YUP] => 1
)

I don't know how efficient it is, but it seems to work. Needed this function in one of my scripts and thought I would share it.

down

szczepan.krolgmail.c0m ¶

5 years ago


Here is a Version with one or more arrays, which have similar values in it:

Use $lower=true/false to ignore/set case Sensitiv.



<?php



$ar1[] = array("red","green","yellow","blue");

$ar1[] = array("green","yellow","brown","red","white","yellow");

$ar1[] = array("red","green","brown","blue","black","yellow");

#$ar1= array("red","green","brown","blue","black","red","green"); // Possible with one or multiple Array



$res = array_icount_values ($ar1);

print_r($res);



function array_icount_values($arr,$lower=true) {

     $arr2=array();

     if(!is_array($arr['0'])){$arr=array($arr);}

     foreach($arr as $k=> $v){

      foreach($v as $v2){

      if($lower==true) {$v2=strtolower($v2);}

      if(!isset($arr2[$v2])){

          $arr2[$v2]=1;

      }else{

           $arr2[$v2]++;

           }

    }

    }

    return $arr2;

}

/*

Will print:

Array

(

    [red] => 3

    [green] => 3

    [yellow] => 4

    [blue] => 2

    [brown] => 2

    [white] => 1

    [black] => 1

)

*/

?>

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pmarcIatIgeneticsImedIharvardIedu ¶

12 years ago


array_count_values function does not work on multidimentional arrays.
If $score[][] is a bidimentional array, the command
"array_count_values ($score)" return the error message "Warning: Can only count STRING and INTEGER values!".

down

-3

manuzhai (AT) php (DOT) net ¶

12 years ago


You might use serialize() to serialize your objects before analyzing their frequency. :)

down

-4

bluej100@gmail ¶

6 years ago


byron at byronrode dot co dot za, here are some benchmarks.



<?php

$haystack = Array();

for ($i = 0; $i < 1000000; $i++) {

  $haystack[] = rand(1, 2000);

}



$needle = rand(1, 2000);



echo "__array_count_values()__\n";

$start = microtime(true);

$startmem = memory_get_usage();

$counts = array_count_values($haystack);

$mem = memory_get_usage()-$startmem;

echo 'Count:'.$counts[$needle]."\n";

echo 'Time:'.(microtime(true) - $start)."\n";

echo 'Memory:'.$mem."\n\n";



echo "__array_keys()__\n";

$start = microtime(true);

$startmem = memory_get_usage();

$keys = array_keys($haystack, $needle);

$mem = memory_get_usage()-$startmem;

echo 'Count:'.count($keys)."\n";

echo 'Time:'.(microtime(true) - $start)."\n";

echo 'Memory:'.$mem."\n\n";



echo '__$needle_array[]__'."\n";

$start = microtime(true);

$startmem = memory_get_usage();

$x = count($haystack);

for($i = 0; $i < $x; $i++){

  if($haystack[$i] == $needle){

    $needle_array[] = $haystack[$i];

  }

}

$mem = memory_get_usage()-$startmem;

$number_of_instances = count($needle_array);

echo 'Count:'.$number_of_instances."\n";

echo 'Time:'.(microtime(true) - $start)."\n";

echo 'Memory:'.$mem."\n\n";



echo '__$number_of_instances++__'."\n";

$start = microtime(true);

$startmem = memory_get_usage();

$x = count($haystack);

$number_of_instances = 0;

for($i = 0; $i < $x; $i++){

  if($haystack[$i] == $needle){

    $number_of_instances++;

  }

}

$mem = memory_get_usage()-$startmem;

echo 'Count:'.$number_of_instances."\n";

echo 'Time:'.(microtime(true) - $start)."\n";

echo 'Memory:'.$mem."\n\n";

?>



[www]mytemp$ php array_count_test.php

__array_count_values()__

Count:515

Time:0.0607650279999

Memory:120328



__array_keys()__

Count:515

Time:0.0869138240814

Memory:33016



__$needle_array[]__

Count:515

Time:0.259949922562

Memory:24792



__$number_of_instances++__

Count:515

Time:0.258481025696

Memory:0



However, when you use an array of strings by calling md5(rand(1, 2000)), the performance boosts become less significant:



__array_count_values()__

Count:499

Time:0.491794109344

Memory:184328



__array_keys()__

Count:499

Time:0.36399102211

Memory:30072



__$needle_array[]__

Count:499

Time:0.568728923798

Memory:22104



__$number_of_instances++__

Count:499

Time:0.574353933334

Memory:0



Results are similar for string->string haystacks with foreach traversal.

down

-4

coda at bobandgeorge dot com ¶

9 years ago


alwaysdrunk's comment only works if you can trust the client web browser. Using this function doesn't validate that every necessary field exists -- only that every field that was submitted has a value in it. Thus if an attacker wished to force a null value into one of the fields, he could (rather easily) construct a modified form without the field and submit THAT.

Besides, you really ought to be validating each field anyway if you're taking user input.

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