array_pad
(PHP 4, PHP 5)
array_pad — Увеличить размер массива до заданной величины
Описание
Функция array_pad() возвращает копию массива input , размер которого был увеличен до значения параметра pad_size элементами со значением pad_value . Если параметр pad_size является положительным числом, то массив увеличивается с конца, если отрицательный - сначала. Если абсолютное значение параметра pad_size меньше или равно размеру массива input , функция не производит никаких операций.
Пример #1 Пример использования array_pad()
$input = array (12, 10, 9);
$result = array_pad ($input, 5, 0);
// результат: array (12, 10, 9, 0, 0)
$result = array_pad ($input, -7, -1);
// результат: array (-1, -1, -1, -1, 12, 10, 9)
$result = array_pad ($input, 2, "noop");
// операция не произведена
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Коментарии
to the previous commenter -- if you read the manual entry, you'd see that a negative pad_size will put the pad values at the front of the array.yes that is true. But, if the index of the array is 2=two, 3=three
and i want 4 more keys to be filled. But, not just filled anywhere, but i want to maintain the key index.
so, i would like to have 0=FILLED, 1=FILLED ... 4=FILLED, 5=FILLED
now i got 4 more keys padded with my string.
We can do this "if" we know the missing keys, but if we dont, then it would be nice for array_pad() or perhaps some new function to do this?
obviously we can achive this by looping through the array using array_key_exists(), and if you dont find the key, simply create + fill it.
regards,
Daarius...
OR you could do this
<?php
$myArr = array(2 => 'three', 3 => 'four');
$newArr = array_pad(array(), 4, 'FILLED');
$newArr =$myArr+$newArr;
?>
This gives your desired result BUT the ordering is a little wierd, because of the order they were added. Indexes are okay though and that is what you wanted.
print_r($newArr) outputs
Array ( [2] => three [3] => four [0] => FILLED [1] => FILLED )
hope this helps
To daarius - you mean you have...
[2]=>"two"
[3]=>"three"
and you want...
[0]=>"FILLED"
[1]=>"FILLED"
[2]=>"two"
[3]=>"three"
[4]=>"FILLED"
[5]=>"FILLED"
If so, then the following code...
<?php
$array = array(2 => "two", 3 => "three");
$array = array_pad($array, count($array)+2, "FILLED");
$num = -(count($array)+2);
$array = array_pad($array, $num, "FILLED");
print_r($array);
?>
will return:
Array ( [0] => FILLED [1] => FILLED [2] => two [3] => three [4] => FILLED [5] => FILLED )
The ordering should be okay,...
little older, a little wiser.
ksort() will order the array back into its normal order again
so:
<?php
$myArr = array(2 => 'two', 4 => 'four');
$newArr = array_pad(array(), 6, 'FILLED');
$newArr =$myArr+$newArr;
ksort($newArr);
?>
Will give :
Array ( [0] => FILLED [1] => FILLED [2] => two [3] => FILLED [4] => four [5] => FILLED )
One way to initialize a 20x20 multidimensional array.
<?php
$a = array();
$b = array();
$b = array_pad($b,20,0);
$a = array_pad($a,20,$b);
?>
Easy way to get an array contains 5 random numbers from 0 to 9:
$rand_arr = array_rand( array_pad( array(), 10, 1 ), 5 );
A simple example for array_pad()
the syntax is as follows: array_pad(array(), (+/-)int, value)
where "array" is the array to which the value is to be added,
"(+/-) int" is a value that decides the length of the array(it should be greater than the length of the array.
if its a negative number then the value will be added at the left of the array else it will be added to the right.
"values" denotes the value to be added to the array
lets try an example:
<?php
$digits = array();
$digits[0] = 1;
$digits[1] = 2;
$digits[2] = 3;
$arraypad = array_pad($digits, -4, "0");
print_r($arraypad);
?>
output:
Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )
Beware, if you try to pad an associative array using numeric keys, your keys will be re-numbered.
<?php
$a = array('size'=>'large', 'number'=>20, 'color'=>'red');
print_r($a);
print_r(array_pad($a, 5, 'foo'));
// use timestamps as keys
$b = array(1229600459=>'large', 1229604787=>20, 1229609459=>'red');
print_r($b);
print_r(array_pad($b, 5, 'foo'));
?>
yields this:
------------------
Array
(
[size] => large
[number] => 20
[color] => red
)
Array
(
[size] => large
[number] => 20
[color] => red
[0] => foo
[1] => foo
)
Array
(
[1229600459] => large
[1229604787] => 20
[1229609459] => red
)
Array
(
[0] => large
[1] => 20
[2] => red
[3] => foo
[4] => foo
)
Just an info about the value of "$pad_size" ,
If we set the value of "$pad_size" from -3 to 3,
It will produce the output like:
<?php
$result = array_pad($input, -3, "noop");
//result is array(12, 10, 9)
$result = array_pad($input, 3, "noop");
//result is array(12, 10, 9)
?>
means array will remain the same.
// insert element to array
function array_insert(&$arr, $pos, $new_el=null) {
$arraypad = array_pad($arr, count($arr)+1, 0);
for ($i=count($arr)-1; $i>=$pos; $i--) {
$arr[$i+1] = $arr[$i];
if ($i == $pos) {
$arr[$i] = $new_el;
}
}
}
$digits = array();
$digits[0] = 0;
$digits[1] = 1;
$digits[2] = 2;
$digits[3] = 3;
$digits[4] = 4;
$digits[5] = 5;
echo "was: "; var_dump($digits);
array_insert($digits, 3, 100);
echo "new: "; var_dump($digits);