array_splice
(PHP 4, PHP 5, PHP 7, PHP 8)
array_splice — 配列の一部を削除し、他の要素で置換する
説明
配列 array
から offset および length
で指定された要素を削除し、配列 replacement
でそれを置換します。
注意:
arrayの配列の数値添字は保存されないことに注意しましょう。
注意:
replacementが配列でない場合は、 型変換 を行います (つまり(array) $replacementとします)。 たとえばreplacementにオブジェクトやnullなどを指定した場合に、 予期せぬ動きをする可能性があります。
パラメータ
array-
入力の配列。
offset-
offsetが正の場合、削除される部分は 配列arrayの最初から指定オフセットの ぶんだけ進んだ位置からとなります。offsetが負の場合、削除される部分は、arrayの末尾から数えた位置からとなります。 length-
lengthが省略された場合、offsetから配列の最後までが全て削除されます。lengthが指定され、正の場合、複数の要素が削除されます。負の
lengthが指定された場合、削除される部分の末尾の位置は配列の末尾を基準にして計算されます。lengthにゼロを指定した場合は、どの要素も削除しません。ヒントreplacementも指定した場合にoffsetから配列の最後まで全てを削除するには、lengthを求めるためにcount($input)を使用してください。 replacement-
配列
replacementが指定された場合、 削除された要素は、この配列の要素で置換されます。offsetおよびlengthで何も削除しないと指定した場合、配列replacementの要素はoffsetで指定された位置に挿入されます。注意:
置換される配列のキーは保存されないことに注意してください。
もし
replacementに一つしか要素がない場合、 要素そのものが配列やオブジェクトあるいはnullでない限り、array()や 角括弧 で括る必要はありません。
戻り値
抽出された要素を含む配列を返します。
変更履歴
| バージョン | 説明 |
|---|---|
| 8.0.0 |
length は、nullable になりました。
|
例
例1 array_splice() の例
<?php
$input = array("red", "green", "blue", "yellow");
array_splice($input, 2);
var_dump($input);
$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, -1);
var_dump($input);
$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, count($input), "orange");
var_dump($input);
$input = array("red", "green", "blue", "yellow");
array_splice($input, -1, 1, array("black", "maroon"));
var_dump($input);
?>上の例の出力は以下となります。
array(2) {
[0]=>
string(3) "red"
[1]=>
string(5) "green"
}
array(2) {
[0]=>
string(3) "red"
[1]=>
string(6) "yellow"
}
array(2) {
[0]=>
string(3) "red"
[1]=>
string(6) "orange"
}
array(5) {
[0]=>
string(3) "red"
[1]=>
string(5) "green"
[2]=>
string(4) "blue"
[3]=>
string(5) "black"
[4]=>
string(6) "maroon"
}
例2 同じ動きをする、array_splice() の様々な例
以下の文は、すべて2つとも同じ意味です:
<?php
// $input に 2 つの要素を追加します
array_push($input, $x, $y);
array_splice($input, count($input), 0, array($x, $y));
// $input の最後の要素を削除します
array_pop($input);
array_splice($input, -1);
// $input の最初の要素を削除します
array_shift($input);
array_splice($input, 0, 1);
// $input の先頭に要素を挿入します
array_unshift($input, $x, $y);
array_splice($input, 0, 0, array($x, $y));
// インデックス $x の $input を置き換えます
$input[$x] = $y; // キーがオフセットと等価な配列に対して
array_splice($input, $x, 1, $y);
?>
＋add a note
User Contributed Notes 38 notes
mrsohailkhan at gmail dot com ¶
13 years ago
array_splice, split an array into 2 arrays. The returned arrays is the 2nd argument actually and the used array e.g $input here contains the 1st argument of array, e.g
<?php
$input = array("red", "green", "blue", "yellow");
print_r(array_splice($input, 3)); // Array ( [0] => yellow )
print_r($input); //Array ( [0] => red [1] => green [2] => blue )
?>
if you want to replace any array value do simple like that,
first search the array index you want to replace
<?php $index = array_search('green', $input);// index = 1 ?>
and then use it as according to the definition
<?php
array_splice($input, $index, 1, array('mygreeen')); //Array ( [0] => red [1] => mygreeen [2] => blue [3] => yellow )
?>
so here green is replaced by mygreen.
here 1 in array_splice above represent the number of items to be replaced. so here start at index '1' and replaced only one item which is 'green'
royanee at yahoo dot com ¶
11 years ago
When trying to splice an associative array into another, array_splice is missing two key ingredients:
- a string key for identifying the offset
- the ability to preserve keys in the replacement array
This is primarily useful when you want to replace an item in an array with another item, but want to maintain the ordering of the array without rebuilding the array one entry at a time.
<?php
function array_splice_assoc(&$input, $offset, $length, $replacement) {
$replacement = (array) $replacement;
$key_indices = array_flip(array_keys($input));
if (isset($input[$offset]) && is_string($offset)) {
$offset = $key_indices[$offset];
}
if (isset($input[$length]) && is_string($length)) {
$length = $key_indices[$length] - $offset;
}
$input = array_slice($input, 0, $offset, TRUE)
+ $replacement
+ array_slice($input, $offset + $length, NULL, TRUE);
}
$fruit = array(
'orange' => 'orange',
'lemon' => 'yellow',
'lime' => 'green',
'grape' => 'purple',
'cherry' => 'red',
);
// Replace lemon and lime with apple
array_splice_assoc($fruit, 'lemon', 'grape', array('apple' => 'red'));
// Replace cherry with strawberry
array_splice_assoc($fruit, 'cherry', 1, array('strawberry' => 'red'));
?>
Note: I have not tested this with negative offsets and lengths.
StanE ¶
9 years ago
array_splice() does not preserve numeric keys. The function posted by "weikard at gmx dot de" won't do that either because array_merge() does not preserve numeric keys either.
Use following function instead:
<?php
function arrayInsert($array, $position, $insertArray)
{
$ret = [];
if ($position == count($array)) {
$ret = $array + $insertArray;
}
else {
$i = 0;
foreach ($array as $key => $value) {
if ($position == $i++) {
$ret += $insertArray;
}
$ret[$key] = $value;
}
}
return $ret;
}
?>
Example:
<?php
$a = [
295 => "Hello",
58 => "world",
];
$a = arrayInsert($a, 1, [123 => "little"]);
/*
Output:
Array
(
[295] => Hello
[123] => little
[58] => world
)
*/
?>
It preserves numeric keys. Note that the function does not use a reference to the original array but returns a new array (I see absolutely no reason how the performance would be increased by using a reference when modifying an array through PHP script code).
daniele centamore ¶
15 years ago
just useful functions to move an element using array_splice.
<?php
// info at danielecentamore dot com
// $input (Array) - the array containing the element
// $index (int) - the index of the element you need to move
function moveUp($input,$index) {
$new_array = $input;
if((count($new_array)>$index) && ($index>0)){
array_splice($new_array, $index-1, 0, $input[$index]);
array_splice($new_array, $index+1, 1);
}
return $new_array;
}
function moveDown($input,$index) {
$new_array = $input;
if(count($new_array)>$index) {
array_splice($new_array, $index+2, 0, $input[$index]);
array_splice($new_array, $index, 1);
}
return $new_array;
}
$input = array("red", "green", "blue", "yellow");
$newinput = moveUp($input, 2);
// $newinput is array("red", "blue", "green", "yellow")
$input = moveDown($newinput, 1);
// $input is array("red", "green", "blue", "yellow")
?>
charette dot s at gmail ¶
14 years ago
If you want to append null values wrap them in an array:
<?php
$a = array('Hey', 'hey', 'my', 'my');
array_splice($a, 1, 0, null);
print_r($a);
?>
Array
(
[0] => Hey
[1] => hey
[2] => my
[3] => my
)
<?php
$b = array('Hey', 'hey', 'my', 'my');
array_splice($b, 1, 0, array(null));
print_r($b);
?>
Array
(
[0] => Hey
[1] =>
[2] => hey
[3] => my
[4] => my
)
gideon at i6developments dot com ¶
20 years ago
array_splice dynamically updates the total number of entries into the array. So for instance I had a case where I needed to insert a value into every 4th entry of the array from the back. The problem was when it added the first, because the total number was dynamically updated, it would only add after the 3rd then the 2nd and so one. The solution I found is to track the number of inserts which were done and account for them dynamically.
Code:
<?php
$modarray = array_reverse($mili);
$trig=1;
foreach($modarray as $rubber => $glue) {
if($rubber!="<BR>") {
$i++;
$b++;
if ($i==4) {
$trig++;
if($trig<=2) {
array_splice($modarray,$b,0,"<BR>");
}elseif($trig>=3){
array_splice($modarray,$b+($trig-2),0,"<BR>");
}
$i=0;
};
};
};
$fixarray = array_reverse($modarray);
?>
weikard at gmx dot de ¶
19 years ago
You cannot insert with array_splice an array with your own key. array_splice will always insert it with the key "0".
<?php
// [DATA]
$test_array = array (
row1 => array (col1 => 'foobar!', col2 => 'foobar!'),
row2 => array (col1 => 'foobar!', col2 => 'foobar!'),
row3 => array (col1 => 'foobar!', col2 => 'foobar!')
);
// [ACTION]
array_splice ($test_array, 2, 0, array ('rowX' => array ('colX' => 'foobar2')));
echo '<pre>'; print_r ($test_array); echo '</pre>';
?>
[RESULT]
Array (
[row1] => Array (
[col1] => foobar!
[col2] => foobar!
)
[row2] => Array (
[col1] => foobar!
[col2] => foobar!
)
[0] => Array (
[colX] => foobar2
)
[row3] => Array (
[col1] => foobar!
[col2] => foobar!
)
)
But you can use the following function:
function array_insert (&$array, $position, $insert_array) {
$first_array = array_splice ($array, 0, $position);
$array = array_merge ($first_array, $insert_array, $array);
}
<?php
// [ACTION]
array_insert ($test_array, 2, array ('rowX' => array ('colX' => 'foobar2')));
echo '<pre>'; print_r ($test_array); echo '</pre>';
?>
[RESULT]
Array (
[row1] => Array (
[col1] => foobar!
[col2] => foobar!
)
[row2] => Array (
[col1] => foobar!
[col2] => foobar!
)
[rowX] => Array (
[colX] => foobar2
)
[row3] => Array (
[col1] => foobar!
[col2] => foobar!
)
)
[NOTE]
The position "0" will insert the array in the first position (like array_shift). If you try a position higher than the langth of the array, you add it to the array like the function array_push.
plintus at smtp dot ru ¶
21 years ago
key-safe:
<?php
function array_kslice ($array, $offset, $length = 0) {
$k = array_slice (array_keys ($array), $offset, $length);
$v = array_slice (array_values ($array), $offset, $length);
for ($i = 0; $i < count ($k); $i ++) $r[$k[$i]] = $v[$i];
return $r;
}
?>
smth like this. hope you like it more than versions above :)
gilberg_vrn ¶
8 years ago
array_splice with preserve keys
<?php
function array_splice_preserve_keys(&$array, $from, $length = null) {
$result = array_slice($array, $from, $length, true);
$array = array_slice($array, $from + $length, null, true);
return $result;
}
?>
Example:
<?php
$array = [
1 => 'a',
2 => 'b',
26 => 'z'
];
var_dump(array_splice_preserve_keys($array, 0, 1), $array);
/**
* array(1) {
* [1]=>
* string(1) "a"
* }
* array(2) {
* [2]=>
* string(1) "b"
* [26]=>
* string(1) "z"
* }
*/
?>
guillaume dot lacourt at gmail dot com ¶
9 years ago
Using array_splice when you traverse array with internal pointer's function reset the array, eg:
<?php
end($arrOfData);
$last = key($arrOfData);
reset($arrOfData);
while (($data = current($arrOfData))) {
if ($last === key($arrOfData)) {
array_splice($arrOfData, $last, 1);
// current($arrOfData) => first value of $arrOfData
}
}
csaba at alum dot mit dot edu ¶
19 years ago
Appending arrays
If you have an array $a2 whose values you would like to append to an array $a1 then four methods you could use are listed below in order of increasing time. The last two methods took significantly more time than the first two. The most surprising lesson is that using the & incurs a time hit.
<?php
foreach ($a2 as $elem) $a1[]=$elem;
foreach ($a2 as &$elem) $a1[]=$elem;
array_splice ($a1, count($a1), 0, $a2);
$a1 = array_merge($a1, $a2);
?>
Csaba Gabor from Vienna
thom ¶
10 years ago
Maybe it will help someone else: I was trying to strip off the last part of an array using this section, more or less as follows:
<?php array_splice($array, $offset); ?>
Now it could occur in my code that <?php $offset === 0 ?>, in which case the array is returned as-is and not, as you might expect, an empty array because everything is stripped off. Obviously it is not really useful anyway to "strip off everything", but I was reminded of that the hard way and this may spare someone some time, hopefully.