array_count_values

(PHP 4, PHP 5, PHP 7, PHP 8)

array_count_values — 配列内に存在する、異なる値の出現回数を数える

説明

array_count_values(array $array): array

array_count_values() は、配列 array の値 (数値または文字列でなければいけません) をキーとし、 array におけるその値の出現回数を値とした配列を返します。

パラメータ

array: 値を数える配列。

戻り値

array のキーとその登場回数を組み合わせた連想配列を返します。

エラー / 例外

string あるいは int 以外の型の要素が登場するたびに E_WARNING が発生します。

例

例1 array_count_values() の例

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

上の例の出力は以下となります。

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

参考

count() - 配列または Countable オブジェクトに含まれるすべての要素の数を数える
array_unique() - 配列から重複した値を削除する
array_values() - 配列の全ての値を返す
count_chars() - 文字列で使用されている文字に関する情報を返す

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User Contributed Notes 3 notes

down

sergolucky96 at gmail dot com ¶

7 years ago

Simple way to find number of items with specific values in multidimensional array:

<?php

$list = [
  ['id' => 1, 'userId' => 5],
  ['id' => 2, 'userId' => 5],
  ['id' => 3, 'userId' => 6],
];
$userId = 5;

echo array_count_values(array_column($list, 'userId'))[$userId]; // outputs: 2
?>

down

rabies dot dostojevski at gmail dot com ¶

18 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 ¶

15 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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