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
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.
其他回答
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;
}
$result_array = array();
$array = array("Tim","John","Mark");
$new_element = "Bill";
$position = 1;
for ($i=0; $i<count($array); $i++)
{
if ($i==$position)
{
$result_array[] = $new_element;
}
$result_array[] = $array[$i];
}
print_r($result_array);
// Result will Array([0] => "Tim",[1] => "Bill", [2] => "John",[1] => "Mark")
这个由Brad Erickson编写的函数用于关联数组:
/* * Inserts a new key/value after the key in the array. * * @param $key * The key to insert after. * @param $array * An array to insert in to. * @param $new_key * The key to insert. * @param $new_value * An value to insert. * * @return * The new array if the key exists, FALSE otherwise. * * @see array_insert_before() */ function array_insert_after($key, array &$array, $new_key, $new_value) { if (array_key_exists($key, $array)) { $new = array(); foreach ($array as $k => $value) { $new[$k] = $value; if ($k === $key) { $new[$new_key] = $new_value; } } return $new; } return FALSE; }
函数来源-这篇博文。还有一个方便的功能,以插入之前特定的关键。
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 $a . ' ';
//returns i am as 1st element
function array_insert($array, $position, $insert) {
if ($position > 0) {
if ($position == 1) {
array_unshift($array, array());
} else {
$position = $position - 1;
array_splice($array, $position, 0, array(
''
));
}
$array[$position] = $insert;
}
return $array;
}
电话的例子:
$array = array_insert($array, 1, ['123', 'abc']);
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