In a piece of software, I merge two arrays with array_merge function. But I need to add the same array (with the same keys, of course) to an existing array.
The problem:
$A = array('a' => 1, 'b' => 2, 'c' => 3);
$B = array('c' => 4, 'd'=> 5);
array_merge($A, $B);
// result
[a] => 1 [b] => 2 [c] => 4 [d] => 5
As you see, 'c' => 3 is missed.
So how can I merge all of them with the same keys?
You need to use array_merge_recursive instead of array_merge. Of course there can only be one key equal to 'c' in the array, but the associated value will be an array containing both 3 and 4.
array_merge to array_merge_recursive and got the same results (array keys renumbered). On PHP.net site, under array_merge, in Example #3 there's a comment: "If you want to append array elements from the second array to the first array while not overwriting the elements from the first array and not re-indexing, use the + array union operator". And that turned to be true in my case. Where did you read, that array_merge_recursive does not renumbers keys?
array_merge_recursive instead of the "plain" version.array_merge and array_merge_recursive are documented to have different behavior for string and integer keys, and for good reason: if they didn't, then the result of array_merge([1], [2]) would be [0 => 2], which is at least "unexpected". So they assume that if you have integer keys, then they don't really matter. If you have integer keys that matter then you must provide explicit logic that takes account of this.Try with array_merge_recursive
$A = [
'a' => 1,
'b' => 2,
'c' => 3,
];
$B = [
'c' => 4,
'd'=> 5,
];
$c = array_merge_recursive($A,$B);
echo "<pre>";
print_r($c);
echo "</pre>";
will return
Array
(
[a] => 1
[b] => 2
[c] => Array
(
[0] => 3
[1] => 4
)
[d] => 5
)
$arr1 = array(
"0" => array("fid" => 1, "tid" => 1, "name" => "Melon"),
"1" => array("fid" => 1, "tid" => 4, "name" => "Tansuozhe"),
"2" => array("fid" => 1, "tid" => 6, "name" => "Chao"),
"3" => array("fid" => 1, "tid" => 7, "name" => "Xi"),
"4" => array("fid" => 2, "tid" => 9, "name" => "Xigua")
);
if you want to convert this array as following:
$arr2 = array(
"0" => array(
"0" => array("fid" => 1, "tid" => 1, "name" => "Melon"),
"1" => array("fid" => 1, "tid" => 4, "name" => "Tansuozhe"),
"2" => array("fid" => 1, "tid" => 6, "name" => "Chao"),
"3" => array("fid" => 1, "tid" => 7, "name" => "Xi")
),
"1" => array(
"0" =>array("fid" => 2, "tid" => 9, "name" => "Xigua")
)
);
so, my answer will be like this:
$outer_array = array();
$unique_array = array();
foreach($arr1 as $key => $value)
{
$inner_array = array();
$fid_value = $value['fid'];
if(!in_array($value['fid'], $unique_array))
{
array_push($unique_array, $fid_value);
unset($value['fid']);
array_push($inner_array, $value);
$outer_array[$fid_value] = $inner_array;
}else{
unset($value['fid']);
array_push($outer_array[$fid_value], $value);
}
}
var_dump(array_values($outer_array));
hope this answer will help somebody sometime.
$A = array('a' => 1, 'b' => 2, 'c' => 3);
$B = array('c' => 4, 'd'=> 5);
$C = array_merge_recursive($A, $B);
$aWhere = array();
foreach ($C as $k=>$v) {
if (is_array($v)) {
$aWhere[] = $k . ' in ('.implode(', ',$v).')';
}
else {
$aWhere[] = $k . ' = ' . $v;
}
}
$where = implode(' AND ', $aWhere);
echo $where;
array_merge_recursiveI just wrote this function, it should do the trick for you, but it does left join
public function mergePerKey($array1,$array2)
{
$mergedArray = [];
foreach ($array1 as $key => $value)
{
if(isset($array2[$key]))
{
$mergedArray[$value] = null;
continue;
}
$mergedArray[$value] = $array2[$key];
}
return $mergedArray;
}
null values.Two entries in an array can't share a key, you'll need to change the key for the duplicate
