如何将一个新项目插入到数组的任何位置,例如在数组的中间?
当前回答
试试这个:
$colors = array('red', 'blue', 'yellow');
$colors = insertElementToArray($colors, 'green', 2);
function insertElementToArray($arr = array(), $element = null, $index = 0)
{
if ($element == null) {
return $arr;
}
$arrLength = count($arr);
$j = $arrLength - 1;
while ($j >= $index) {
$arr[$j+1] = $arr[$j];
$j--;
}
$arr[$index] = $element;
return $arr;
}
其他回答
如果你想保留初始数组的键,并添加一个有键的数组,那么使用下面的函数:
function insertArrayAtPosition( $array, $insert, $position ) {
/*
$array : The initial array i want to modify
$insert : the new array i want to add, eg array('key' => 'value') or array('value')
$position : the position where the new array will be inserted into. Please mind that arrays start at 0
*/
return array_slice($array, 0, $position, TRUE) + $insert + array_slice($array, $position, NULL, TRUE);
}
电话的例子:
$array = insertArrayAtPosition($array, array('key' => 'Value'), 3);
在做了几天之后,这是我能找到的最简单的解决方案。
$indexnumbertoaddat // this is a variable that points to the index # where you
want the new array to be inserted
$arrayToAdd = array(array('key' => $value, 'key' => $value)); //this is the new
array and it's values that you want to add. //the key here is to write it like
array(array('key' =>, since you're adding this array inside another array. This
is the point that a lot of answer left out.
array_splice($originalArray, $indexnumbertoaddatt, 0, $arrayToAdd); //the actual
splice function. You're doing it to $originalArray, at the index # you define,
0 means you're just shifting all other index items down 1, and then you add the
new array.
在数组开头添加元素的提示:
$a = array('first', 'second');
$a[-1] = 'i am the new first element';
然后:
foreach($a as $aelem)
echo $a . ' ';
//returns first, second, i am...
but:
for ($i = -1; $i < count($a)-1; $i++)
echo $a . ' ';
//returns i am as 1st element
$a = array(1, 2, 3, 4);
$b = array_merge(array_slice($a, 0, 2), array(5), array_slice($a, 2));
// $b = array(1, 2, 5, 3, 4)
要将元素插入到具有字符串键的数组中,您可以这样做:
/* insert an element after given array key
* $src = array() array to work with
* $ins = array() to insert in key=>array format
* $pos = key that $ins will be inserted after
*/
function array_insert_string_keys($src,$ins,$pos) {
$counter=1;
foreach($src as $key=>$s){
if($key==$pos){
break;
}
$counter++;
}
$array_head = array_slice($src,0,$counter);
$array_tail = array_slice($src,$counter);
$src = array_merge($array_head, $ins);
$src = array_merge($src, $array_tail);
return($src);
}