downloads | documentation | faq | getting help | mailing lists | licenses | wiki | reporting bugs | php.net sites | conferences | my php.net

search for in the

array_pop> <array_multisort
[edit] Last updated: Fri, 17 May 2013

view this page in

array_pad

(PHP 4, PHP 5)

array_pad 用值将数组填补到指定长度

说明

array array_pad ( array $input , int $pad_size , mixed $pad_value )

array_pad() 返回 input 的一个拷贝,并用 pad_value 将其填补到 pad_size 指定的长度。如果 pad_size 为正,则数组被填补到右侧,如果为负则从左侧开始填补。如果 pad_size 的绝对值小于或等于 input 数组的长度则没有任何填补。有可能一次最多填补 1048576 个单元。

参数

input

Initial array of values to pad.

pad_size

New size of the array.

pad_value

Value to pad if input is less than pad_size.

返回值

Returns a copy of the input padded to size specified by pad_size with value pad_value. If pad_size is positive then the array is padded on the right, if it's negative then on the left. If the absolute value of pad_size is less than or equal to the length of the input then no padding takes place.

范例

Example #1 array_pad() 例子

<?php
$input 
= array(12109);

$result array_pad($input50);
// result is array(12, 10, 9, 0, 0)

$result array_pad($input, -7, -1);
// result is array(-1, -1, -1, -1, 12, 10, 9)

$result array_pad($input2"noop");
// not padded
?>

参见

  • array_fill() - 用给定的值填充数组
  • range() - 建立一个包含指定范围单元的数组



array_pop> <array_multisort
[edit] Last updated: Fri, 17 May 2013
 
add a note add a note User Contributed Notes array_pad - [11 notes]
up
2
mwwaygoo at hotmail dot com
10 years ago
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
up
1
goffrie at sympatico dot ca
10 years ago
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,...
up
2
tugla
4 years ago
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
)
up
1
mwwaygoo at hotmail dot com
9 years ago
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 )
up
0
oaev at mail dot ru
8 years ago
Easy way to get an array contains 5 random numbers from 0 to 9:

$rand_arr = array_rand( array_pad( array(), 10, 1 ), 5 );
up
0
Anonymous
9 years ago
One way to initialize a 20x20 multidimensional array. 

<?php
$a
= array();
$b = array();
$b = array_pad($b,20,0);
$a = array_pad($a,20,$b);
?>
up
-1
sonu50imedbvu at gmail dot com(Sonu Jaiswal)
2 years ago
Just an info about the value of "$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.
up
-1
hk, StrApp Bussiness Solutions
6 years ago
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 )
up
0
scott*hurring.com
10 years ago
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.
up
-1
daarius at hotmail dot com
10 years ago
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...
up
-1
ethanhunt314 at hotmail dot com
12 years ago
This is useful when using next() and prev() function in a while loop to traverse an array.

For example the following code will only output up to 8.

<?php
$test
[] = "1";
$test[] = "2";
$test[] = "3";
$test[] = "4";
$test[] = "5";
$test[] = "6";
$test[] = "7";
$test[] = "8";
$test[] = "9";
$test[] = "10";
$test[] = " ";
$test[] = " ";
$test[] = " ";

$count = count($test);

while(
$i < $count) {

$now = current($test);
echo
"<p>$now</p>";

next($test);
next($test);
next($test);
prev($test);
prev($test);
prev($test);


$i++;
next($test);
}
?>

But if you use:
$test = array_pad($test, 13, " ");

you will get all of your output.

 
show source | credits | sitemap | contact | advertising | mirror sites