假设我们有两个数组:
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
$array_2 = array(
'zero' => '0',
'one' => '1',
'two' => '2',
'three' => '3',
);
现在，我想在每个数组的第三个元素后插入数组('sample_key' => 'sample_value')。我该怎么做呢?
当前回答
我需要一些可以在键之前，替换，之后插入的东西;如果没有找到目标键，则在数组的开头或结尾添加。默认是在键后插入。
新功能
/**
* Insert element into an array at a specific key.
*
* @param array $input_array
* The original array.
* @param array $insert
* The element that is getting inserted; array(key => value).
* @param string $target_key
* The key name.
* @param int $location
* 1 is after, 0 is replace, -1 is before.
*
* @return array
* The new array with the element merged in.
*/
function insert_into_array_at_key(array $input_array, array $insert, $target_key, $location = 1) {
$output = array();
$new_value = reset($insert);
$new_key = key($insert);
foreach ($input_array as $key => $value) {
if ($key === $target_key) {
// Insert before.
if ($location == -1) {
$output[$new_key] = $new_value;
$output[$key] = $value;
}
// Replace.
if ($location == 0) {
$output[$new_key] = $new_value;
}
// After.
if ($location == 1) {
$output[$key] = $value;
$output[$new_key] = $new_value;
}
}
else {
// Pick next key if there is an number collision.
if (is_numeric($key)) {
while (isset($output[$key])) {
$key++;
}
}
$output[$key] = $value;
}
}
// Add to array if not found.
if (!isset($output[$new_key])) {
// Before everything.
if ($location == -1) {
$output = $insert + $output;
}
// After everything.
if ($location == 1) {
$output[$new_key] = $new_value;
}
}
return $output;
}
输入代码
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
$array_2 = array(
'zero' => '0',
'one' => '1',
'two' => '2',
'three' => '3',
);
$array_1 = insert_into_array_at_key($array_1, array('sample_key' => 'sample_value'), 2, 1);
print_r($array_1);
$array_2 = insert_into_array_at_key($array_2, array('sample_key' => 'sample_value'), 'two', 1);
print_r($array_2);
输出
Array
(
[0] => zero
[1] => one
[2] => two
[sample_key] => sample_value
[3] => three
)
Array
(
[zero] => 0
[one] => 1
[two] => 2
[sample_key] => sample_value
[three] => 3
)
其他回答
如果你只是想在数组的某个位置插入一个项(基于@clausvdb的答案):
function array_insert($arr, $insert, $position) {
$i = 0;
$ret = array();
foreach ($arr as $key => $value) {
if ($i == $position) {
$ret[] = $insert;
}
$ret[] = $value;
$i++;
}
return $ret;
}
该函数支持:
数字键和关联键 在建立键之前或之后插入 如果key未建立，则附加到数组末尾
function insert_into_array( $array, $search_key, $insert_key, $insert_value, $insert_after_founded_key = true, $append_if_not_found = false ) {
$new_array = array();
foreach( $array as $key => $value ){
// INSERT BEFORE THE CURRENT KEY?
// ONLY IF CURRENT KEY IS THE KEY WE ARE SEARCHING FOR, AND WE WANT TO INSERT BEFORE THAT FOUNDED KEY
if( $key === $search_key && ! $insert_after_founded_key )
$new_array[ $insert_key ] = $insert_value;
// COPY THE CURRENT KEY/VALUE FROM OLD ARRAY TO A NEW ARRAY
$new_array[ $key ] = $value;
// INSERT AFTER THE CURRENT KEY?
// ONLY IF CURRENT KEY IS THE KEY WE ARE SEARCHING FOR, AND WE WANT TO INSERT AFTER THAT FOUNDED KEY
if( $key === $search_key && $insert_after_founded_key )
$new_array[ $insert_key ] = $insert_value;
}
// APPEND IF KEY ISNT FOUNDED
if( $append_if_not_found && count( $array ) == count( $new_array ) )
$new_array[ $insert_key ] = $insert_value;
return $new_array;
}
用法:
$array1 = array(
0 => 'zero',
1 => 'one',
2 => 'two',
3 => 'three',
4 => 'four'
);
$array2 = array(
'zero' => '# 0',
'one' => '# 1',
'two' => '# 2',
'three' => '# 3',
'four' => '# 4'
);
$array3 = array(
0 => 'zero',
1 => 'one',
64 => '64',
3 => 'three',
4 => 'four'
);
// INSERT AFTER WITH NUMERIC KEYS
print_r( insert_into_array( $array1, 3, 'three+', 'three+ value') );
// INSERT AFTER WITH ASSOC KEYS
print_r( insert_into_array( $array2, 'three', 'three+', 'three+ value') );
// INSERT BEFORE
print_r( insert_into_array( $array3, 64, 'before-64', 'before-64 value', false) );
// APPEND IF SEARCH KEY ISNT FOUNDED
print_r( insert_into_array( $array3, 'undefined assoc key', 'new key', 'new value', true, true) );
结果:
Array
(
[0] => zero
[1] => one
[2] => two
[3] => three
[three+] => three+ value
[4] => four
)
Array
(
[zero] => # 0
[one] => # 1
[two] => # 2
[three] => # 3
[three+] => three+ value
[four] => # 4
)
Array
(
[0] => zero
[1] => one
[before-64] => before-64 value
[64] => 64
[3] => three
[4] => four
)
Array
(
[0] => zero
[1] => one
[64] => 64
[3] => three
[4] => four
[new key] => new value
)
代码:
function insertValueAtPosition($arr, $insertedArray, $position) {
$i = 0;
$new_array=[];
foreach ($arr as $key => $value) {
if ($i == $position) {
foreach ($insertedArray as $ikey => $ivalue) {
$new_array[$ikey] = $ivalue;
}
}
$new_array[$key] = $value;
$i++;
}
return $new_array;
}
例子:
$array = ["A"=8, "K"=>3];
$insert_array = ["D"= 9];
insertValueAtPosition($array, $insert_array, $position=2);
// result ====> ["A"=>8, "D"=>9, "K"=>3];
也许看起来不完美，但很有效。
我需要一些可以在键之前，替换，之后插入的东西;如果没有找到目标键，则在数组的开头或结尾添加。默认是在键后插入。
新功能
/**
* Insert element into an array at a specific key.
*
* @param array $input_array
* The original array.
* @param array $insert
* The element that is getting inserted; array(key => value).
* @param string $target_key
* The key name.
* @param int $location
* 1 is after, 0 is replace, -1 is before.
*
* @return array
* The new array with the element merged in.
*/
function insert_into_array_at_key(array $input_array, array $insert, $target_key, $location = 1) {
$output = array();
$new_value = reset($insert);
$new_key = key($insert);
foreach ($input_array as $key => $value) {
if ($key === $target_key) {
// Insert before.
if ($location == -1) {
$output[$new_key] = $new_value;
$output[$key] = $value;
}
// Replace.
if ($location == 0) {
$output[$new_key] = $new_value;
}
// After.
if ($location == 1) {
$output[$key] = $value;
$output[$new_key] = $new_value;
}
}
else {
// Pick next key if there is an number collision.
if (is_numeric($key)) {
while (isset($output[$key])) {
$key++;
}
}
$output[$key] = $value;
}
}
// Add to array if not found.
if (!isset($output[$new_key])) {
// Before everything.
if ($location == -1) {
$output = $insert + $output;
}
// After everything.
if ($location == 1) {
$output[$new_key] = $new_value;
}
}
return $output;
}
输入代码
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
$array_2 = array(
'zero' => '0',
'one' => '1',
'two' => '2',
'three' => '3',
);
$array_1 = insert_into_array_at_key($array_1, array('sample_key' => 'sample_value'), 2, 1);
print_r($array_1);
$array_2 = insert_into_array_at_key($array_2, array('sample_key' => 'sample_value'), 'two', 1);
print_r($array_2);
输出
Array
(
[0] => zero
[1] => one
[2] => two
[sample_key] => sample_value
[3] => three
)
Array
(
[zero] => 0
[one] => 1
[two] => 2
[sample_key] => sample_value
[three] => 3
)
不像Artefacto的答案那么具体，但基于他使用array_slice()的建议，我写了下一个函数:
function arrayInsert($target, $byKey, $byOffset, $valuesToInsert, $afterKey) {
if (isset($byKey)) {
if (is_numeric($byKey)) $byKey = (int)floor($byKey);
$offset = 0;
foreach ($target as $key => $value) {
if ($key === $byKey) break;
$offset++;
}
if ($afterKey) $offset++;
} else {
$offset = $byOffset;
}
$targetLength = count($target);
$targetA = array_slice($target, 0, $offset, true);
$targetB = array_slice($target, $offset, $targetLength, true);
return array_merge($targetA, $valuesToInsert, $targetB);
}
特点:
插入一个或múltiple值 插入键值对 在键前/键后插入，或按偏移量插入
使用例子:
$target = [
'banana' => 12,
'potatoe' => 6,
'watermelon' => 8,
'apple' => 7,
2 => 21,
'pear' => 6
];
// Values must be nested in an array
$insertValues = [
'orange' => 0,
'lemon' => 3,
3
];
// By key
// Third parameter is not applicable
// Insert after 2 (before 'pear')
var_dump(arrayInsert($target, 2, null, $valuesToInsert, true));
// Insert before 'watermelon'
var_dump(arrayInsert($target, 'watermelon', null, $valuesToInsert, false));
// By offset
// Second and last parameter are not applicable
// Insert in position 2 (zero based i.e. before 'watermelon')
var_dump(arrayInsert($target, null, 2, $valuesToInsert, null));
