假设我们有两个数组:
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
$array_2 = array(
'zero' => '0',
'one' => '1',
'two' => '2',
'three' => '3',
);
现在，我想在每个数组的第三个元素后插入数组('sample_key' => 'sample_value')。我该怎么做呢?
当前回答
如果你不知道你想在位置3插入它，但你知道你想在后面插入它的键，在看到这个问题后，我想出了这个小函数。
/**
* Inserts any number of scalars or arrays at the point
* in the haystack immediately after the search key ($needle) was found,
* or at the end if the needle is not found or not supplied.
* Modifies $haystack in place.
* @param array &$haystack the associative array to search. This will be modified by the function
* @param string $needle the key to search for
* @param mixed $stuff one or more arrays or scalars to be inserted into $haystack
* @return int the index at which $needle was found
*/
function array_insert_after(&$haystack, $needle = '', $stuff){
if (! is_array($haystack) ) return $haystack;
$new_array = array();
for ($i = 2; $i < func_num_args(); ++$i){
$arg = func_get_arg($i);
if (is_array($arg)) $new_array = array_merge($new_array, $arg);
else $new_array[] = $arg;
}
$i = 0;
foreach($haystack as $key => $value){
++$i;
if ($key == $needle) break;
}
$haystack = array_merge(array_slice($haystack, 0, $i, true), $new_array, array_slice($haystack, $i, null, true));
return $i;
}
这里是一个代码板小提琴看到它的行动:http://codepad.org/5WlKFKfz
注意:array_splice()会比array_merge(array_slice())更有效，但这样你插入的数组的键就会丢失。叹息。
其他回答
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
)
我这样做
$slightly_damaged = array_merge(
array_slice($slightly_damaged, 0, 4, true) + ["4" => "0.0"],
array_slice($slightly_damaged, 4, count($slightly_damaged) - 4, true)
);
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, $position=2);
// result ====> ["A"=>8, "D"=>9, "K"=>3];
也许看起来不完美，但很有效。
如果你不知道你想在位置3插入它，但你知道你想在后面插入它的键，在看到这个问题后，我想出了这个小函数。
/**
* Inserts any number of scalars or arrays at the point
* in the haystack immediately after the search key ($needle) was found,
* or at the end if the needle is not found or not supplied.
* Modifies $haystack in place.
* @param array &$haystack the associative array to search. This will be modified by the function
* @param string $needle the key to search for
* @param mixed $stuff one or more arrays or scalars to be inserted into $haystack
* @return int the index at which $needle was found
*/
function array_insert_after(&$haystack, $needle = '', $stuff){
if (! is_array($haystack) ) return $haystack;
$new_array = array();
for ($i = 2; $i < func_num_args(); ++$i){
$arg = func_get_arg($i);
if (is_array($arg)) $new_array = array_merge($new_array, $arg);
else $new_array[] = $arg;
}
$i = 0;
foreach($haystack as $key => $value){
++$i;
if ($key == $needle) break;
}
$haystack = array_merge(array_slice($haystack, 0, $i, true), $new_array, array_slice($haystack, $i, null, true));
return $i;
}
这里是一个代码板小提琴看到它的行动:http://codepad.org/5WlKFKfz
注意:array_splice()会比array_merge(array_slice())更有效，但这样你插入的数组的键就会丢失。叹息。
