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
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
)
其他回答
以下是我的看法:
/**
*
* Insert an element after an index in an array
* @param array $array
* @param string|int $key
* @param mixed $value
* @param string|int $offset
* @return mixed
*/
function array_splice_associative($array, $key, $value, $offset) {
if (!is_array($array)) {
return $array;
}
if (array_key_exists($key, $array)) {
unset($array[$key]);
}
$return = array();
$inserted = false;
foreach ($array as $k => $v) {
$return[$k] = $v;
if ($k == $offset && !$inserted) {
$return[$key] = $value;
$inserted = true;
}
}
if (!$inserted) {
$return[$key] = $value;
}
return $return;
}
这里有一个你可以使用的简单函数。只要插进去就行了。
这是按索引插入，而不是按值插入。
您可以选择传递该数组，或者使用已经声明的数组。
较新的、较短的版本:
function insert($array, $index, $val)
{
$size = count($array); //because I am going to use this more than one time
if (!is_int($index) || $index < 0 || $index > $size)
{
return -1;
}
else
{
$temp = array_slice($array, 0, $index);
$temp[] = $val;
return array_merge($temp, array_slice($array, $index, $size));
}
}
更老、更长的版本:
function insert($array, $index, $val) { //function decleration
$temp = array(); // this temp array will hold the value
$size = count($array); //because I am going to use this more than one time
// Validation -- validate if index value is proper (you can omit this part)
if (!is_int($index) || $index < 0 || $index > $size) {
echo "Error: Wrong index at Insert. Index: " . $index . " Current Size: " . $size;
echo "<br/>";
return false;
}
//here is the actual insertion code
//slice part of the array from 0 to insertion index
$temp = array_slice($array, 0, $index);//e.g index=5, then slice will result elements [0-4]
//add the value at the end of the temp array// at the insertion index e.g 5
array_push($temp, $val);
//reconnect the remaining part of the array to the current temp
$temp = array_merge($temp, array_slice($array, $index, $size));
$array = $temp;//swap// no need for this if you pass the array cuz you can simply return $temp, but, if u r using a class array for example, this is useful.
return $array; // you can return $temp instead if you don't use class array
}
使用的例子:
//1
$result = insert(array(1,2,3,4,5),0, 0);
echo "<pre>";
echo "<br/>";
print_r($result);
echo "</pre>";
//2
$result = insert(array(1,2,3,4,5),2, "a");
echo "<pre>";
print_r($result);
echo "</pre>";
//3
$result = insert(array(1,2,3,4,5) ,4, "b");
echo "<pre>";
print_r($result);
echo "</pre>";
//4
$result = insert(array(1,2,3,4,5),5, 6);
echo "<pre>";
echo "<br/>";
print_r($result);
echo "</pre>";
预期结果:
//1
Array
(
[0] => 0
[1] => 1
[2] => 2
[3] => 3
[4] => 4
[5] => 5
)
//2
Array
(
[0] => 1
[1] => 2
[2] => a
[3] => 3
[4] => 4
[5] => 5
)
//3
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => b
[5] => 5
)
//4
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
[5] => 6
)
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
)
你可以在foreach循环中插入元素，因为这个循环工作在原始数组的副本上，但是你必须跟踪插入的行数(在这段代码中我称之为“膨胀”):
$bloat=0;
foreach ($Lines as $n=>$Line)
{
if (MustInsertLineHere($Line))
{
array_splice($Lines,$n+$bloat,0,"string to insert");
++$bloat;
}
}
显然，您可以推广这种“膨胀”思想来处理foreach循环期间的任意插入和删除。
对于第一个数组，使用array_splice():
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
array_splice($array_1, 3, 0, 'more');
print_r($array_1);
输出:
Array(
[0] => zero
[1] => one
[2] => two
[3] => more
[4] => three
)
对于第二个，没有顺序，所以你只需要做:
$array_2['more'] = '2.5';
print_r($array_2);
把钥匙按你想要的排序。
