current() also works on objects:
<?php
echo current((object) array('one', 'two')); // Outputs: one
?>
current
(PHP 4, PHP 5, PHP 7)
current — Retorna o elemento corrente em um array
Descrição
Todo array tem um ponteiro interno para o elemento "atual", o qual é inicializado para apontar para o primeiro elemento inserido em um array.
Parâmetros
-
array -
O array.
Valor Retornado
A função current() simplesmente retorna
o elemento do array para o qual esse ponteiro interno está apontando.
Não move o ponteiro de forma alguma. Se o ponteiro interno
estiver apontando para além do final da lista de elementos ou o array é vazio,
current() retorna false.
Aviso
Esta função pode
retornar o booleano false, mas também pode retornar um valor não-booleano que pode ser
avaliado como false, como 0 ou
"". Leia a seção em Booleanos para maiores
informações. Utilize o operador ===
para testar o valor retornado por esta função.
Exemplos
Exemplo #1 Exemplo do uso de current() e amigos
<?php
$transport = array('foot', 'bike', 'car', 'plane');
$mode = current($transport); // $mode = 'foot';
$mode = next($transport); // $mode = 'bike';
$mode = current($transport); // $mode = 'bike';
$mode = prev($transport); // $mode = 'foot';
$mode = end($transport); // $mode = 'plane';
$mode = current($transport); // $mode = 'plane';
$arr = array();
var_dump(current($arr)); // bool(false)
$arr = array(array());
var_dump(current($arr)); // array(0) { }
?>
Notas
Nota: Você não será capaz de distinguir o fim de um array de um elemento boolean
false. Para percorer um array que pode conter elementosfalse, veja a função each().
Veja Também
- end() - Faz o ponteiro interno de um array apontar para o seu último elemento
- key() - Retorna uma chave de um array
- each() - Retorna o par chave/valor corrente de um array e avança o seu cursor
- prev() - Retrocede o ponteiro interno de um array
- reset() - Faz o ponteiro interno de um array apontar para o seu primeiro elemento
- next() - Avança o ponteiro interno de um array
add a note
User Contributed Notes 14 notes
michael at squiloople dot com ¶
11 years ago
Vasily Yudin (st-2 at mail dot ru) ¶
8 years ago
If you do current() after using uset() on foreach statement, you can get FALSE in PHP version 5.2.4 and above.
There is example:
<?php
$prices = array(
0 => '1300990',
1 => '500',
2 => '600'
);
foreach($prices as $key => $price){
if($price < 1000){
unset($prices[$key]);
}
}
var_dump(current($prices)); // bool(false)
?>
If you do unset() without foreach? all will be fine.
<?php
$prices = array(
0 => '1300990',
1 => '500',
2 => '600'
);
unset($prices[1]);
unset($prices[2]);
var_dump(current($prices));
?>
strate at yandex dot com ¶
9 years ago
Note, that you can pass array by expression, not only by reference (as described in doc).
<?php
var_dump( current( array(1,2,3) ) ); // (int) 1
?>
mdeng at kabenresearch dot com ¶
19 years ago
For large array(my sample was 80000+ elements), if you want to traverse the array in sequence, using array index $a[$i] could be very inefficient(very slow). I had to switch to use current($a).
vaclav dot sir at gmail dot com ¶
15 years ago
To that "note": You won't be able to distinguish the end of an array from a boolean FALSE element, BUT you can distinguish the end from a NULL value of the key() function.
Example:
<?php
if (key($array) === null) {
echo "You are in the end of the array.";
} else {
echo "Current element: " . current($array);
}
?>
xedin dot unknown at gmail dot com ¶
4 years ago
Array functions, such as `current()` and `rewind()` will work on `Traversable` as well, PHP 5.0 - 7.3, but not in HHVM:
<?php
$queue = new ArrayIterator(array('adasdasd'));
reset($queue);
$current = current($queue);
var_dump($current);
?>
See https://3v4l.org/VjCHR
retestro_REMOVE at SPAM_esperanto dot org dot il ¶
20 years ago
The docs do not specify this, but adding to the array using the brackets syntax:
<?php $my_array[] = $new_value; ?>
will not advance the internal pointer of the array. therefore, you cannot use current() to get the last value added or key() to get the key of the most recently added element.
You should do an end($my_array) to advance the internal pointer to the end ( as stated in one of the notes on end() ), then
<?php
$last_key = key($my_array); // will return the key
$last_value = current($my_array); // will return the value
?>
If you have no need in the key, $last_value = end($my_array) will also do the job.
- Sergey.
vitalib at 012 dot net dot il ¶
19 years ago
Note that by copying an array its internal pointer is lost:
<?php
$myarray = array(0=>'a', 1=>'b', 2=>'c');
next($myarray);
print_r(current($myarray));
echo '<br>';
$a = $myarray;
print_r(current($a));
?>
Would output 'b' and then 'a' since the internal pointer wasn't copied. You can cope with that problem using references instead, like that:
<?php
$a =& $myarray;
?>
leozmm at outlook dot com ¶
3 years ago
Array can be passed by both REFERENCE and EXPRESSION on `current`, because current doesn't move array's internal pointer,
this is not true for other functions like: `end`, `next`, `prev` etc.
<?php
function foo() {return array(1,2,3);}
echo current(foo()); // this print '1'
echo end(foo()); // this print error: Only variables should be passed by reference
?>
pdarmis at gmail dot com ¶
5 years ago
Based on this example http://php.net/manual/en/function.current.php#116128 i would like to add the following. As Vasily points out in his example
<?php
$prices = array(
0 => '1300990',
1 => '500',
2 => '600'
);
foreach($prices as $key => $price){
if($price < 1000){
unset($prices[$key]);
}
}
var_dump(current($prices)); // bool(false)
?>
The above example will not work and return false for version of PHP between 5.2.4 and 5.6.29. The issue is not present on PHP versions >= 7.0.1
A different workaround (at least from Vasily's example) would be to use reset() before using current() in order to reset the array pointer to start.
<?php
$prices = array(
0 => '1300990',
1 => '500',
2 => '600'
);
foreach($prices as $key => $price){
if($price < 1000){
unset($prices[$key]);
}
}
reset($prices);
var_dump(current($prices)); // string(7) "1300990"
?>
gregory at gregory dot net ¶
15 years ago
It took me a while to figure this out, but there is a more consistent way to figure out whether you really went past the end of the array, than using each().
You see, each() gets the value BEFORE advancing the pointer, and next() gets the value AFTER advancing the pointer. When you are implementing the Iterator interface, therefore, it's a real pain in the behind to use each().
And thus, I give you the solution:
To see if you've blown past the end of the array, use key($array) and see if it returns NULL. If it does, you're past the end of the array -- keys can't be null in arrays.
Nifty, huh? Here's how I implemented the Iterator interface in one of my classes:
<?php
/**
* DbRow file
* @package PalDb
*/
/**
* This class lets you use Db rows and object-relational mapping functionality.
*/
class DbRow implements Iterator
{
/**
* The DbResult object that gave us this row through fetchDbRows
* @var DbResult
*/
protected $result;
/**
* The fields of the row
* @var $fields
*/
protected $fields;
/**
* Constructor
*
* @param PDOStatement $stmt
* The PDO statement object that this result uses
* @param DbResult $result
* The result that produced this row through fetchDbRows
*/
function __construct($result)
{
$this->result = $result;
}
/**
* Get the DbResult object that gave us this row through fetchDbRows
* @return DbResult
*
* @return unknown
*/
function getResult()
{
return $this->result;
}
function __set(
$name,
$value)
{
$this->fields[$name] = $value;
}
function __get(
$name)
{
if (isset($this->fields[$name]))
return $this->fields[$name];
else
return null;
}
/**
* Iterator implementation - rewind
*/
function rewind()
{
$this->beyondLastField = false;
return reset($this->fields);
}
function valid()
{
return !$this->beyondLastField;
}
function current()
{
return current($this->fields);
}
function key()
{
return key($this->fields);
}
function next()
{
$next = next($this->fields);
$key = key($this->fields);
if (isset($key)) {
return $next[1];
} else {
$this->beyondLastField = true;
return false; // doesn't matter what we return here, see valid()
}
}
private $beyondLastField = false;
};
Hope this helps someone.
aefxx ¶
15 years ago
A simple copy function that not only copies the given array but ensures the copy's pointer is set to the exact same position:
<?php
function array_copy(&array)
{
$key = key($array);
$copy = $array;
while (($copy_key = key($copy)) !== NULL) {
if ($copy_key == $key) break;
next($copy);
}
return $copy;
}
?>
That's all ... bye.
Pratip Ghosh ¶
9 years ago
If we unset any element from an array, and then try the current function, I noted it returned FALSE. To overcome this limitation, you can use array_values function to re-order the tree.
jodevweb at gmail dot com ¶
6 years ago
As Sergey stated a long time ago in this notes, when adding to the array using the brackets syntax, current won't return the last added value. Instead of moving the pointer with end(), you simply can get the last value with <?php $my_array[count($my_array) - 1] ?> (only applies to a non-associative array).
