count

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

    count — Conta todos os elementos de um array ou de um objeto Countable

    Descrição

    count(Countable|array $value, int $mode = COUNT_NORMAL): int

    Conta todos os elementos de um array quando usado com um array. Quando usado com um objeto que implementa a interface Countable, retorna o valor de retorno do método Countable::count().

    Parâmetros

    value

    Um array ou objeto Countable.

    mode

    Se o parâmetro opcional mode for definido para COUNT_RECURSIVE (ou 1), a função count() irá recursivamente contar o array. Isto é particularmente útil para contar todos os elementos de um array multidimensional.

    Cuidado

    count() pode detectar recursividade para evitar um loop infinito, mas irá emitir um aviso E_WARNING cada vez que o fizer (caso o array contenha a si mesmo mais de uma vez) e retornará uma contagem maior que a esperada.

    Valor Retornado

    Retorna o número de elementos em value. Antes do PHP 8.0.0, se o parâmetro não fosse um array nem um object que implementa a interface Countable, 1 seria retornado, a menos que value fosse null, e neste caso 0 seria retornado.

    Registro de Alterações

    Versão Descrição
    8.0.0 count() irá agora disparar TypeError em tipos contáveis inválidos passados no parâmetro value.
    7.2.0 count() irá agora emitir um aviso em tipos contáveis inválidos passados no parâmetro value.

    Exemplos

    Exemplo #1 Exemplo da função count()

    <?php
    $a    [0] = 1;
    $a[1] = 3;
    $a[2] = 5;
    var_dump(count($a));

    $b[0] = 7;
    $b[5] = 9;
    $b[10] = 11;
    var_dump(count($b));
    ?>

    O exemplo acima produzirá:

    int(3)
int(3)

    Exemplo #2 Exemplo de count() em não-Countable|array (contra exemplo - não deve ser feito)

    <?php
    $b    [0] = 7;
    $b[5] = 9;
    $b[10] = 11;
    var_dump(count($b));

    var_dump(count(null));

    var_dump(count(false));
    ?>

    O exemplo acima produzirá:

    int(3)
int(0)
int(1)

    Saída do exemplo acima no PHP 7.2:

    int(3)

Warning: count(): Parameter must be an array or an object that implements Countable in … on line 12
int(0)

Warning: count(): Parameter must be an array or an object that implements Countable in … on line 14
int(1)

    Saída do exemplo acima no PHP 8:

    int(3)

Fatal error: Uncaught TypeError: count(): Argument #1 ($var) must be of type Countable .. on line 12

    Exemplo #3 Uso recursivo da função count()

    <?php
    $comidas     = array('frutas' => array('laranja', 'banana', 'maçã'),
    'vegetais' => array('cenoura', 'couve', 'ervilha'));

    // contagem recursiva
    var_dump(count($comidas, COUNT_RECURSIVE));

    // contagem normal
    var_dump(count($comidas));

    ?>

    O exemplo acima produzirá:

    int(8)
int(2)

    Exemplo #4 Objeto Countable

    <?php
    class CountOfMethods implements Countable
    {
    private function     someMethod()
    {
    }

    public function     count(): int
    {
    return     count(get_class_methods($this));
    }
    }

    $obj = new CountOfMethods();
    var_dump(count($obj));
    ?>

    O exemplo acima produzirá:

    int(2)

    Veja Também

    • is_array() - Verifica se a variável é um array
    • isset() - Determina se uma variável está declarada e é diferente de null
    • empty() - Determina se uma variável está vazia
    • strlen() - Retorna o tamanho de uma string
    • is_countable() - Verifica se o conteúdo de uma variável é um valor contável
    • Arrays

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    Notas Enviadas por Usuários (em inglês) 13 notes

    up
    141
    onlyranga at gmail dot com
    10 years ago
    [Editor's note: array at from dot pl had pointed out that count() is a cheap operation; however, there's still the function call overhead.]

    If you want to run through large arrays don't use count() function in the loops , its a over head in performance, copy the count() value into a variable and use that value in loops for a better performance.

    Eg:

    // Bad approach

    for($i=0;$i<count($some_arr);$i++)
    {
    // calculations
    }

    // Good approach

    $arr_length = count($some_arr);
    for($i=0;$i<$arr_length;$i++)
    {
    // calculations
    }
    up
    4
    lucasfsmartins at gmail dot com
    5 years ago
    If you are on PHP 7.2+, you need to be aware of "Changelog" and use something like this:

    <?php
    $countFruits     = is_array($countFruits) || $countFruits instanceof Countable ? count($countFruits) : 0;
    ?>

    You can organize your code to ensure that the variable is an array, or you can extend the Countable so that you don't have to do this check.
    up
    3
    Anonymous
    5 years ago
    For a Non Countable Objects

    $count = count($data);
    print "Count: $count\n";

    Warning: count(): Parameter must be an array or an object that implements Countable in example.php on line 159

    #Quick fix is to just cast the non-countable object as an array..

    $count = count((array) $data);
    print "Count: $count\n";

    Count: 250
    up
    13
    danny at dannymendel dot com
    17 years ago
    I actually find the following function more useful when it comes to multidimension arrays when you do not want all levels of the array tree.

    // $limit is set to the number of recursions
    <?php
    function count_recursive ($array, $limit) {
    $count = 0;
    foreach (    $array as $id => $_array) {
    if (    is_array ($_array) && $limit > 0) {
    $count += count_recursive ($_array, $limit - 1);
    } else {
    $count += 1;
    }
    }
    return     $count;
    }
    ?>
    up
    4
    pied-pierre
    9 years ago
    A function of one line to find the number of elements that are not arrays, recursively :

    function count_elt($array, &$count=0){
    foreach($array as $v) if(is_array($v)) count_elt($v,$count); else ++$count;
    return $count;
    }
    up
    9
    alexandr at vladykin dot pp dot ru
    18 years ago
    My function returns the number of elements in array for multidimensional arrays subject to depth of array. (Almost COUNT_RECURSIVE, but you can point on which depth you want to plunge).

    <?php
    function getArrCount ($arr, $depth=1) {
    if (!    is_array($arr) || !$depth) return 0;

    $res=count($arr);

    foreach (    $arr as $in_ar)
    $res+=getArrCount($in_ar, $depth-1);

    return     $res;
    }
    ?>
    up
    0
    olja dot fb at gmail dot com
    1 year ago
    In example #3, given as:

    <?php
    $food     = array('fruits' => array('orange', 'banana', 'apple'),
    'veggie' => array('carrot', 'collard', 'pea'));

    // recursive count
    var_dump(count($food, COUNT_RECURSIVE));
    ?>

    with the output given as int(8), it may have some readers mistaken, as I was at first: one might take it as keys being counted as well as the inner array entries:

    <?php
    // NO:
    'fruits', 'orange', 'banana', 'apple',
    'veggie', 'carrot', 'collard', 'pea'
    ?>

    But actually keys are not counted in count function, and why it is still 8 - because inner arrays are counted as entries as well as their inner elements:

    <?php
    // YES:
    array('orange', 'banana', 'apple'), 'orange', 'banana', 'apple',
    array(    'carrot', 'collard', 'pea'), 'carrot', 'collard', 'pea'
    ?>
    up
    -1
    php_count at cubmd dot com
    7 years ago
    All the previous recursive count solutions with $depth option would not avoid infinite loops in case the array contains itself more than once.
    Here's a working solution:

    <?php
    /**
    * Recursively count elements in an array. Behaves exactly the same as native
    * count() function with the $depth option. Meaning it will also add +1 to the
    * total count, for the parent element, and not only counting its children.
    * @param $arr
    * @param int $depth
    * @param int $i (internal)
    * @return int
    */
    public static function countRecursive(&$arr, $depth = 0, $i = 0) {
    $i++;
    /**
    * In case the depth is 0, use the native count function
    */
    if (empty($depth)) {
    return     count($arr, COUNT_RECURSIVE);
    }
    $count = 0;
    /**
    * This can occur only the first time when the method is called and $arr is not an array
    */
    if (!is_array($arr)) {
    return     count($arr);
    }

    // if this key is present, it means you already walked this array
    if (isset($arr['__been_here'])) {
    return     0;
    }

    $arr['__been_here'] = true;

    foreach (    $arr as $key => &$value) {
    if (    $key !== '__been_here') {
    if (    is_array($value) && $depth > $i) {
    $count += self::countRecursive($value, $depth, $i);
    }

    $count++;
    }
    }

    // you need to unset it when done because you're working with a reference...
    unset($arr['__been_here']);
    return     $count;
    }
    ?>
    up
    -1
    asma mechtaba
    2 years ago
    count and sizeof are aliases, what work for one works for the other.
    up
    -2
    Christoph097
    2 years ago
    Empty values are counted:
    <?php
    $ar    [] = 3;
    $ar[] = null;
    var_dump(count($ar)); //int(2)
    ?>
    up
    -5
    buyatv at gmail dot com
    7 years ago
    You can not get collect sub array count when there is only one sub array in an array:

    $a = array ( array ('a','b','c','d'));
    $b = array ( array ('a','b','c','d'), array ('e','f','g','h'));

    echo count($a); // 4 NOT 1, expect 1
    echo count($b); // 2, expected
    up
    -5
    vojtaripa at gmail dot com
    4 years ago
    To get the count of the inner array you can do something like:

    $inner_count = count($array[0]);
    echo ($inner_count);
    up
    -4
    max at schimmelmann dot org
    4 years ago
    In special situations you might only want to count the first level of the array to figure out how many entries you have, when they have N more key-value-pairs.

    <?php

    $data     = [
    'a' => [
    'bla1' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    'bla2' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    'bla3' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    'bla4' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    ],
    'b' => [
    'bla1' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    'bla2' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ],
    ],
    'c' => [
    'bla1' => [
    0 => 'asdf',
    1 => 'asdf',
    2 => 'asdf',
    ]
    ]
    ];
    $count = array_sum(array_values(array_map('count', $data)));
    // will return int(7)
    var_dump($count);

    // will return 31
    var_dump(count($data, 1));
    ?>
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