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
可以在整数和字符串位置进行插入的函数:
/**
* @param array $array
* @param int|string $position
* @param mixed $insert
*/
function array_insert(&$array, $position, $insert)
{
if (is_int($position)) {
array_splice($array, $position, 0, $insert);
} else {
$pos = array_search($position, array_keys($array));
$array = array_merge(
array_slice($array, 0, $pos),
$insert,
array_slice($array, $pos)
);
}
}
整数的用法:
$arr = ["one", "two", "three"];
array_insert(
$arr,
1,
"one-half"
);
// ->
array (
0 => 'one',
1 => 'one-half',
2 => 'two',
3 => 'three',
)
字符串的用法:
$arr = [
"name" => [
"type" => "string",
"maxlength" => "30",
],
"email" => [
"type" => "email",
"maxlength" => "150",
],
];
array_insert(
$arr,
"email",
[
"phone" => [
"type" => "string",
"format" => "phone",
],
]
);
// ->
array (
'name' =>
array (
'type' => 'string',
'maxlength' => '30',
),
'phone' =>
array (
'type' => 'string',
'format' => 'phone',
),
'email' =>
array (
'type' => 'email',
'maxlength' => '150',
),
)
其他回答
没有本地PHP函数(据我所知)可以完全完成您的请求。
我已经写了2个我认为适合目的的方法:
function insertBefore($input, $index, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
$originalIndex = 0;
foreach ($input as $key => $value) {
if ($key === $index) {
$tmpArray[] = $element;
break;
}
$tmpArray[$key] = $value;
$originalIndex++;
}
array_splice($input, 0, $originalIndex, $tmpArray);
return $input;
}
function insertAfter($input, $index, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
$originalIndex = 0;
foreach ($input as $key => $value) {
$tmpArray[$key] = $value;
$originalIndex++;
if ($key === $index) {
$tmpArray[] = $element;
break;
}
}
array_splice($input, 0, $originalIndex, $tmpArray);
return $input;
}
虽然速度更快,而且可能更节省内存,但这只适用于不需要维护数组键的地方。
如果你确实需要维护密钥,下面的方法会更合适;
function insertBefore($input, $index, $newKey, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
foreach ($input as $key => $value) {
if ($key === $index) {
$tmpArray[$newKey] = $element;
}
$tmpArray[$key] = $value;
}
return $input;
}
function insertAfter($input, $index, $newKey, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
foreach ($input as $key => $value) {
$tmpArray[$key] = $value;
if ($key === $index) {
$tmpArray[$newKey] = $element;
}
}
return $tmpArray;
}
$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)
通常,使用标量值:
$elements = array('foo', ...);
array_splice($array, $position, $length, $elements);
要在数组中插入一个数组元素,不要忘记将数组包装在数组中(因为它是一个标量值!):
$element = array('key1'=>'value1');
$elements = array($element);
array_splice($array, $position, $length, $elements);
否则,数组的所有键都将逐条添加。
你可以试试,用这个方法让它变得简单
/**
* array insert element on position
*
* @link https://vector.cool
*
* @since 1.01.38
*
* @param array $original
* @param mixed $inserted
* @param int $position
* @return array
*/
function array_insert(&$original, $inserted, int $position): array
{
array_splice($original, $position, 0, array($inserted));
return $original;
}
$columns = [
['name' => '預約項目', 'column' => 'item_name'],
['name' => '預約時間', 'column' => 'start_time'],
['name' => '預約姓名', 'column' => 'full_name'],
['name' => '連絡電話', 'column' => 'phone'],
['name' => '建立時間', 'column' => 'create_time']
];
$col = ['name' => '預約帳戶', 'column' => 'user_id'];
$columns = array_insert($columns, $col, 3);
print_r($columns);
打印:
Array
(
[0] => Array
(
[name] => 預約項目
[column] => item_name
)
[1] => Array
(
[name] => 預約時間
[column] => start_time
)
[2] => Array
(
[name] => 預約姓名
[column] => full_name
)
[3] => Array
(
[name] => 報名人數1
[column] => num_of_people
)
[4] => Array
(
[name] => 連絡電話
[column] => phone
)
[5] => Array
(
[name] => 預約帳戶
[column] => user_id
)
[6] => Array
(
[name] => 建立時間
[column] => create_time
)
)
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;
}