PHP 5.4.31 Released

array_fill

(PHP 4 >= 4.2.0, PHP 5)

array_fillRiempie un array con i valori specificati

Descrizione

array array_fill ( int $inizio , int $num , mixed $valore )

array_fill() riempie un array con num elementi inizializzati con il valore del parametro valore, e con le chiavi che partono dal valore del parametro start_index. Si noti che num deve essere un valore maggiore di zero, altrimenti PHP mostrerà un avvertimento.

Example #1 esempio di array_fill()

<?php
$a 
array_fill(56'banana');
print_r($a);
?>

$a ora è:

Array
(
    [5]  => banana
    [6]  => banana
    [7]  => banana
    [8]  => banana
    [9]  => banana
    [10] => banana
)

Vedere anche str_repeat() e range().

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User Contributed Notes 6 notes

up
7
csst0266 at cs dot uoi dot gr
9 years ago
This is what I recently did to quickly create a two dimensional array (10x10), initialized to 0:

<?php
  $a
= array_fill(0, 10, array_fill(0, 10, 0));
?>

This should work for as many dimensions as you want, each time passing to array_fill() (as the 3rd argument) another array_fill() function.
up
6
miguelxpain at gmail dot com
2 years ago
I made this function named "array_getMax" that returns te maximum value and index, from array:

<?php
//using array_search_all by helenadeus at gmail dot com

function array_search_all($needle, $haystack)
{
#array_search_match($needle, $haystack) returns all the keys of the values that match $needle in $haystack

   
foreach ($haystack as $k=>$v) {
  
        if(
$haystack[$k]==$needle){
      
          
$array[] = $k;
        }
    }
    return (
$array);

  
}

function
array_getMax($array){
       
   
$conteo=array_count_values($array);
   
    if(
count($conteo)==1 ){//returns full array when all values are the same.
       
return  $array;      
    }
      
   
arsort($array);
   
   
//$antValue=null;
   
$maxValue=null;
   
$keyValue=null;
    foreach(
$array as $key=>$value){
        if(
$maxValue==null){
           
$maxValue=$value;
           
$keyValue=$key;
            break;
        }       
    }
   
   
$resultSearch=array_search_all($maxValue, $array);
       
   return 
array_fill_keys($resultSearch, $maxValue);
   
   
}

//example
 
$arreglo=array('e1'=>99,'e2'=>'99','e3'=>1,'e4'=>1,'e5'=>98);
   
   
var_dump(array_getMax($arreglo));

//output
/*
array(2) {
  ["e1"]=>
  int(99)
  ["e2"]=>
  int(99)
}
*/
?>

I hope some one find this usefull
up
2
user at stress dot com
6 months ago
$numeri = array();
        if ($n >= 2) {
            $numeriPrimi = array();
            //for($y=0; $y <= $n; $y++) $numeri[$y] = 1;
            $numeri=array_fill(0, ($n+1), 1);
            $maxChk = (int)sqrt($n);
            for ($x=2; $x <= $maxChk; $x++) {
                if (is_np($x, $numeriPrimi)) {
                    $numeriPrimi[] = $x;
                    for ($t = 2; ($x*$t) <= $n; $t++) {
                        unset($numeri[$x*$t]);
                    }
                }
            }
        }
        unset($numeri[0]);
        unset($numeri[1]);
        $numeriPrimi = array_keys($numeri);
        return $numeriPrimi;
up
0
anatoliy at ukhvanovy dot name
1 month ago
If you need negative indices:
<?php
$b
= array_fill(-2, 4, 'pear');//this is not what we want
$c = array_fill_keys(range(-2,1),'pear');//these are negative indices
print_r($b);
print_r($c);
?>
Here is result of the code above:
Array
(
    [-2] => pear
    [0] => pear
    [1] => pear
    [2] => pear
)
Array
(
    [-2] => pear
    [-1] => pear
    [0] => pear
    [1] => pear
)
up
0
Anonymous
11 years ago
array_fill() cannot be used to setup only missing keys in an array. This  may be necessary for example before using implode()  on a sparse filled array.
The solution is to use this function:

<?php
function array_setkeys(&$array, $fill = NULL) {
 
$indexmax = -1;
  for (
end($array); $key = key($array); prev($array)) {
    if (
$key > $indexmax)
     
$indexmax = $key;
  }
  for (
$i = 0; $i <= $indexmax; $i++) {
    if (!isset(
$array[$i]))
     
$array[$i] = $fill;
  }
 
ksort($array);
}
?>

This is usefull in some situations where you don't know which key index was filled and you want to preserve the association between a positioned field in an imploded array and the key index when exploding it.
up
-1
mchljnk at NOSPAM dot gmail dot com
8 months ago
Using objects with array_fill may cause unexpected results. Consider the following:

<?php
class Foo {
   public
$bar = "banana";
}

//fill an array with objects
$array = array_fill(0, 2, new Foo());

var_dump($array);
/*
array(2) {
  [0]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(6) "banana"
  }
  [1]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(6) "banana"
  }
} */

//now we change the attribute of the object stored in index 0
//this actually changes the attribute for EACH object in the ENTIRE array
$array[0]->bar = "apple";

var_dump($array);
/*
array(2) {
  [0]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(5) "apple"
  }
  [1]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(5) "apple"
  }
}
*/
?>

Objects are filled in the array BY REFERENCE. They are not copied for each element in the array.
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