Array Funzioni

Vedere anche:

Vedere anche le funzioni is_array(), explode(), implode(), split(), preg_split() e unset().

Indice dei contenuti

  • array_change_key_case — Restituisce un array con tutte le chiavi cambiate in maiuscolo o in minuscolo
  • array_chunk — Spezza un array in tronconi
  • array_column — Return the values from a single column in the input array
  • array_combine — Crea un'array utilizzando un'array per le chiavi ed un altro per i suoi valori
  • array_count_values — Conta tutti i valori di un array
  • array_diff_assoc — Calcola la differenza tra due o più array con un ulteriore controllo sull'indice
  • array_diff_key — Computes the difference of arrays using keys for comparison
  • array_diff_uassoc — Computes the difference of arrays with additional index check which is performed by a user supplied callback function
  • array_diff_ukey — Computes the difference of arrays using a callback function on the keys for comparison
  • array_diff — Calcola la differenza di due o più array
  • array_fill_keys — Fill an array with values, specifying keys
  • array_fill — Riempie un array con i valori specificati
  • array_filter — Filtra gli elementi di un array usando una funzione callback
  • array_flip — Scambia tutte le chiavi di un array con i loro valori associati
  • array_intersect_assoc — Calcola l'intersezione degli array con un ulteriore controllo sugli indici
  • array_intersect_key — Computes the intersection of arrays using keys for comparison
  • array_intersect_uassoc — Computes the intersection of arrays with additional index check, compares indexes by a callback function
  • array_intersect_ukey — Computes the intersection of arrays using a callback function on the keys for comparison
  • array_intersect — Calcola l'intersezione degli arrays
  • array_key_exists — Controlla se l'indice (o chiave) specificato esiste nell'array
  • array_key_first — Gets the first key of an array
  • array_key_last — Gets the last key of an array
  • array_keys — Restituisce tutte le chiavi di un array
  • array_map — Applica la funzione callback a tutti gli elementi dell'array dato
  • array_merge_recursive — Fonde due o più array in modo ricorsivo
  • array_merge — Fonde uno o più array
  • array_multisort — Ordina array multipli o multidimensionali
  • array_pad — Riempie con un valore un array fino alla lunghezza specificata
  • array_pop — Estrae l'elemento alla fine dell'array
  • array_product — Calculate the product of values in an array
  • array_push — Accoda uno o più elementi ad un array
  • array_rand — Estrae a caso uno o più elementi da un array
  • array_reduce — Riduce iterativamente l'array a un singolo valore utilizzando una funzione callback
  • array_replace_recursive — Replaces elements from passed arrays into the first array recursively
  • array_replace — Replaces elements from passed arrays into the first array
  • array_reverse — Restituisce un array con gli elementi in ordine invertito
  • array_search — Ricerca un dato valore in un array e ne restituisce la chiave corrispondente, se la ricerca ha successo.
  • array_shift — Estrae l'elemento alla testa dell'array
  • array_slice — Estrae un sottoinsieme da un array
  • array_splice — Rimuove una porzione dell'array e la sostituisce con altro
  • array_sum — Calcola la somma dei valori di un array
  • array_udiff_assoc — Computes the difference of arrays with additional index check, compares data by a callback function
  • array_udiff_uassoc — Computes the difference of arrays with additional index check, compares data and indexes by a callback function
  • array_udiff — Computes the difference of arrays by using a callback function for data comparison
  • array_uintersect_assoc — Computes the intersection of arrays with additional index check, compares data by a callback function
  • array_uintersect_uassoc — Computes the intersection of arrays with additional index check, compares data and indexes by separate callback functions
  • array_uintersect — Computes the intersection of arrays, compares data by a callback function
  • array_unique — Rimuove i valori duplicati di un array
  • array_unshift — Inserisce uno o più elementi all'inizio dell'array
  • array_values — Restituisce tutti i valori di un array
  • array_walk_recursive — Apply a user function recursively to every member of an array
  • array_walk — Esegue una funzione su ogni elemento dell'array
  • array — Crea un array
  • arsort — Ordina un array in ordine decrescente e mantiene le associazioni degli indici
  • asort — Ordina un array e mantiene le associazioni degli indici
  • compact — Crea un array contenente variabili e il loro valore
  • count — Conta gli elementi in una variabile, o le proprietà in un oggetto
  • current — Restituisce l'elemento corrente di un array
  • each — Restituisce la corrente coppia chiave/valore di un array e incrementa il puntatore dell'array
  • end — Sposta il puntatore interno dell'array all'ultimo elemento
  • extract — Importa le variabili nella tabella dei simboli
  • in_array — Controlla se un valore è presente in un array
  • key_exists — Alias di array_key_exists
  • key — Estrae la chiave corrente da un array associativo
  • krsort — Ordina rispetto alle chiavi di un array in ordine inverso
  • ksort — Ordina rispetto alle chiavi di un array
  • list — Assegna valori a delle variabili come se fossero un array
  • natcasesort — Ordina un array usando un algoritmo di "ordine naturale" non sensibile alle maiuscole/minuscole
  • natsort — Ordina un array usando un algoritmo di "ordine naturale"
  • next — Incrementa il puntatore interno dell'array
  • pos — Restituisce l'elemento corrente di un array
  • prev — Decrementa il puntatore interno dell'array
  • range — Crea un array contenente una serie di elementi
  • reset — Reimposta il puntatore interno di un array sulla posizione iniziale
  • rsort — Ordina un array in ordine decrescente
  • shuffle — Mescola un array
  • sizeof — Alias di count
  • sort — Ordina un array
  • uasort — Ordina un array mediante una funzione definita dall'utente e mantiene le associazioni
  • uksort — Ordina rispetto alle chiavi di un array mediante una funzione definita dall'utente
  • usort — Ordina un array mediante una funzione definita dall'utente
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User Contributed Notes 13 notes

up
0
indioeuropeo at driverop dot com
1 year ago
I need to take an element from the Array and change its position within the Array by moving the rest of the elements as required.
This is the function that does it. The first parameter is the working Array. The second is the position of the element to move and the third is the position where to move the element.
The function returns the modified Array.
<?php
function array_move_elem($array, $from, $to) {
    if (
$from == $to) { return $array; }
   
$c = count($array);
    if ((
$c > $from) and ($c > $to)) {
        if (
$from < $to) {
           
$f = $array[$from];
            for (
$i = $from; $i < $to; $i++) {
               
$array[$i] = $array[$i+1];
            }
           
$array[$to] = $f;
        } else {
           
$f = $array[$from];
            for (
$i = $from; $i > $to; $i--) {
               
$array[$i] = $array[$i-1];
            }
           
$array[$to] = $f;
        }
       
    }
    return
$array;
}

?>
Examples:
<?php
$array
= array('Cero','Uno','Dos','Tres','Cuatro','Cinco','Seis','Siete','Ocho','Nueve','Diez');
$array = array_move_elem($array, 3, 5); // Move element in position 3 to position 5...
print_r($array);

$array = array_move_elem($array, 5, 3); // Move element in position 5 to position 3, leaving array as it was... ;)
print_r($array);

?>
Return:
<?php
Array ( [0] => Cero [1] => Uno [2] => Dos [3] => Cuatro [4] => Cinco [5] => Tres [6] => Seis [7] => Siete [8] => Ocho [9] => Nueve [10] => Diez )
Array ( [
0] => Cero [1] => Uno [2] => Dos [3] => Tres [4] => Cuatro [5] => Cinco [6] => Seis [7] => Siete [8] => Ocho [9] => Nueve [10] => Diez )
?>
up
0
permanovd at gmail dot com
2 years ago
A simple trick that can help you to guess what diff/intersect or sort function does by name.

[suffix] assoc - additional index check. Compares both value and index.

Example: array_diff_assoc, array_intersect_assoc.

[suffix] key - index only check. Ignores value of array, compares only indexes.

Example: array_diff_key, array_intersect_key.

[suffix] **empty** - no "key" or "assoc" word in suffix. Compares values only. Ignores indexes of array.

Example: array_diff, array_intersect.

[prefix] u - will do comparison with user defined function. Letter u can be used twice in some functions (like array_udiff_uassoc), this means that you have to use 2 functions (one for value, one for index).

Example: array_udiff_uassoc, array_uintersect_assoc.

This also works with array sort functions:

[prefix] a - associative. Will preserve keys.

Example: arsort, asort.

[prefix] k - key sort. Will sort array by keys.

Example: uksort, ksort.

[prefix] r - reverse. Will sort array in reverse order.

Example: rsort, krsort.

[prefix] u - sort by user defined function (same as for diff/intersect).

Example: usort, uasort.
up
0
kolkabes at googlemail dot com
8 years ago
Short function for making a recursive array copy while cloning objects on the way.

<?php
function arrayCopy( array $array ) {
       
$result = array();
        foreach(
$array as $key => $val ) {
            if(
is_array( $val ) ) {
               
$result[$key] = arrayCopy( $val );
            } elseif (
is_object( $val ) ) {
               
$result[$key] = clone $val;
            } else {
               
$result[$key] = $val;
            }
        }
        return
$result;
}
?>
up
-1
renatonascto at gmail dot com
11 years ago
Big arrays use a lot of memory possibly resulting in memory limit errors. You can reduce memory usage on your script by destroying them as soon as you´re done with them. I was able to get over a few megabytes of memory by simply destroying some variables I didn´t use anymore.
You can view the memory usage/gain by using the funcion memory_get_usage(). Hope this helps!
up
-6
dave at davidhbrown dot us
8 years ago
While PHP has well over three-score array functions, array_rotate is strangely missing as of PHP 5.3. Searching online offered several solutions, but the ones I found have defects such as inefficiently looping through the array or ignoring keys.

The following array_rotate() function uses array_merge and array_shift to reliably rotate an array forwards or backwards, preserving keys. If you know you can trust your $array to be an array and $shift to be between 0 and the length of your array, you can skip the function definition and use just the return expression in your code.

<?php
function array_rotate($array, $shift) {
    if(!
is_array($array) || !is_numeric($shift)) {
        if(!
is_array($array)) error_log(__FUNCTION__.' expects first argument to be array; '.gettype($array).' received.');
        if(!
is_numeric($shift)) error_log(__FUNCTION__.' expects second argument to be numeric; '.gettype($shift)." `$shift` received.");
        return
$array;
    }
   
$shift %= count($array); //we won't try to shift more than one array length
   
if($shift < 0) $shift += count($array);//handle negative shifts as positive
   
return array_merge(array_slice($array, $shift, NULL, true), array_slice($array, 0, $shift, true));
}
?>
A few simple tests:
<?php
$array
=array("foo"=>1,"bar"=>2,"baz"=>3,4,5);

print_r(array_rotate($array, 2));
print_r(array_rotate($array, -2));
print_r(array_rotate($array, count($array)));
print_r(array_rotate($array, "4"));
print_r(array_rotate($array, -9));
?>
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-10
ob at babcom dot biz
13 years ago
Here is a function to find out the maximum depth of a multidimensional array.

<?php
// return depth of given array
// if Array is a string ArrayDepth() will return 0
// usage: int ArrayDepth(array Array)

function ArrayDepth($Array,$DepthCount=-1,$DepthArray=array()) {
 
$DepthCount++;
  if (
is_array($Array))
    foreach (
$Array as $Key => $Value)
     
$DepthArray[]=ArrayDepth($Value,$DepthCount);
  else
    return
$DepthCount;
  foreach(
$DepthArray as $Value)
   
$Depth=$Value>$Depth?$Value:$Depth;
  return
$Depth;
}
?>
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-12
Ewan
3 years ago
I was looking for an array aggregation function here and ended up writing this one.

Note: This implementation assumes that none of the fields you're aggregating on contain The '@' symbol.

<?php
 
function array_group_by($flds, $arr) {
   
$groups = array();
    foreach (
$arr as $rec) {
     
$keys = array_map(function($f) use($rec) { return $rec[$f]; }, $flds);
     
$k = implode('@', $keys);
      if (isset(
$groups[$k])) {
       
$groups[$k][] = $rec;
      } else {
       
$groups[$k] = array($rec);
      }
    }
    return
$groups;
  }

?>
up
-16
callmeanaguma at gmail dot com
7 years ago
If you need to flattern two-dismensional array with single values assoc subarrays, you could use this function:

<?php
function arrayFlatten($array) {
       
$flattern = array();
        foreach (
$array as $key => $value){
           
$new_key = array_keys($value);
           
$flattern[] = $value[$new_key[0]];
        }
        return
$flattern;
}
?>
up
-11
DamianKaelGreen at gmail dot com
3 years ago
While there are a lot of array functions in the PHP libs, there also seem to be a lot of rudimentary ones missing.

I went ahead and created several of my own functions for handling multiple non-associative (na) arrays including:

na_array_merge
na_array_intersect
na_array_diff
na_array_xnor
na_array_xor

If you are using Venn diagrams to think about your arrays, then these functions might be for you.

I have made them available and posted documentation for them here: https://www.greendingle.com/some-useful-non-associative-array-functions/
up
-16
cyberchrist at futura dot net
12 years ago
Lately, dealing with databases, I've been finding myself needing to know if one array, $a, is a proper subset of $b.

Mathematically, this is asking (in set theory) [excuse the use of u and n instead of proper Unicode):

( A u B ) n ( ~ B )

What this does is it first limits to known values, then looks for anything outside of B but in the union of A and B (which would be those things in A which are not also in B).

If any value exists in this set, then A is NOT a proper subset of B, because a value exists in A but not in B.  For A to be a proper subset, all values in A must be in B.

I'm sure this could easily be done any number of ways but this seems to work for me.  It's not got a lot of error detection such as sterilizing inputs or checking input types.

// bool array_subset( array, array )
// Returns true if $a is a proper subset of $b, returns false otherwise.

function array_subset( $a, $b )
{
    if( count( array_diff( array_merge($a,$b), $b)) == 0 )
        return true;
    else
        return false;
}
up
-18
nicoolasens at gmail dot com
4 years ago
/*to change an index without rewriting the whole table and leave at the same place.
*/
<?php
function change_index(&$tableau, $old_key, $new_key) {
   
$changed = FALSE;
   
$temp = 0;
    foreach (
$tableau as $key => $value) {
        switch (
$changed) {
            case
FALSE :
               
//creates the new key and deletes the old
               
if ($key == $old_key) {
                   
$tableau[$new_key] = $tableau[$old_key];
                    unset(
$tableau[$old_key]);
                   
$changed = TRUE;
                }
                break;

            case
TRUE :
               
//moves following keys
               
if ($key != $new_key){
               
$temp= $tableau[$key];
                unset(
$tableau[$key]);
               
$tableau[$key] = $temp;
                break;
                }
                else {
$changed = FALSE;} //stop
       
}
    }
   
array_values($tableau); //free_memory
}

//Result :
$tableau = array(1, 2 , 3, 4,5, 6, 7, 8, 9, 10);
$res = print_r($tableau, TRUE);
$longueur = strlen($res) -1;
echo
"Old array :\n" . substr($res, 8, $longueur) . "\n" ;

change_index ($tableau, 2, 'number 2');
$res = print_r($tableau, TRUE);
$longueur = strlen($res) -10;
echo
"New array :\n" . substr($res, 8, $longueur) . "\n" ;

/*
Old array :
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
    [6] => 7
    [7] => 8
    [8] => 9
    [9] => 10
)

New array :
    [0] => 1
    [1] => 2
    [numéro 2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
    [6] => 7
    [7] => 8
    [8] => 9
    [9] => 10
*/
?>
up
-19
mo dot longman at gmail dot com
12 years ago
to 2g4wx3:
i think better way for this is using JSON, if you have such module in your PHP. See json.org.

to convert JS array to JSON string: arr.toJSONString();
to convert JSON string to PHP array: json_decode($jsonString);

You can also stringify objects, numbers, etc.
up
-21
oliverSPAMMENOT at e-geek dot com dot au
10 years ago
Function to pretty print arrays and objects. Detects object recursion and allows setting a maximum depth. Based on arraytostring and u_print_r from the print_r function notes. Should be called like so:

<?php
egvaluetostring
($value)   //no max depth, or
egvaluetostring($value, $max_depth)   //max depth set

function egvaluetostring($value, $max_depth, $key = NULL, $depth = 0, $refChain = array()) {
  if(
$depth > 0)
   
$tab = str_repeat("\t", $depth);
 
$text .= $tab . ($key !== NULL ? $key . " => " : "");
 
  if (
is_array($value) || is_object($value)) {
   
$recursion = FALSE;
    if (
is_object($value)) {
      foreach (
$refChain as $refVal) {
        if (
$refVal === $value) {
         
$recursion = TRUE;
          break;
        }
      }
     
array_push($refChain, $value);
    }
   
   
$text .= (is_array($value) ? "array" : "object") . " ( ";
   
    if (
$recursion) {
     
$text .= "*RECURSION* ";
    }
    elseif (isset(
$max_depth) && $depth >= $max_depth) {
     
$text .= "*MAX DEPTH REACHED* ";
    }
    else {
      if (!empty(
$value)) {
       
$text .= "\n";
        foreach (
$value as $child_key => $child_value) {
         
$text .= egvaluetostring($child_value, $max_depth, (is_array($value) ? "[" : "") . $child_key . (is_array($value) ? "]" : ""), $depth+1, $refChain) . ",\n";
        }
       
$text .= "\n" . $tab;
      }
    }
   
   
$text .= ")";
   
    if (
is_object($value)) {
     
array_pop($refChain);
    }
  }
  else {
   
$text .= "$value";
  }

  return
$text;
}
?>
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