If the input arrays contain numeric keys, the later value will be appended instead of overriding the original value. But consider the following code where key '3' is string not integer. javascript array concat spread operator . This is my version of array_merge_recursive without overwriting numeric keys: This function didn't work for me - or it didn't do what I thought it would. For those who are getting duplicate entries when using this function, there is a very easy solution: Old behavior of array_merge can be restored by simple  variable type casting like this, Similar to Jo I had a problem merging arrays (thanks for that Jo you kicked me out of my debugging slumber) - array_merge does NOT act like array_push, as I had anticipated. Example #3 array_merge() with non-array types. Although it may not be apparent, if using array_merge_recursive in a loop to combine results from a database query or some other function, you can corrupt your result when NULLs are present in the data. The first argument provides the keys for the new array while … Example #1 array_merge_recursive() example. one are appended to the end of the previous one. It returns the resulting array. PHP array_merge_recursive() Function. It returns the resulting array. Example: It would seem that array_merge doesn't do anything when one array is empty (unset): Note that if you use + to merge array in order to preserve keys, that in case of duplicates the values from the left array in the addition is used. It is not officially documented but it is summarily important information for everyone to know: neither array_merge or array_merge_recursive functions will function correctly if non-array objects  are used as parameters. PHP Code: It returns the resulting array. Variable list of arrays to recursively merge. exists in both arrays, then the element from the first array will If the input arrays have matching string keys, then the later value will override it's the previous counterpart. Returns the resulting array. If you want to append array elements from the second array to the I found the "simple" method of adding arrays behaves differently as described in the documentation in PHP v5.2.0-10. function will merge it with a corresponding entry in another array “es6 merge two arrays by value” Code Answer’s. The array_merge function does not preserve numeric key values. array_merge_recursive() merges the elements of Of course there can only be one key equal to 'c' in the array, but the associated value will be php - Merging arrays with the same keys - Stack Overflow. I've changes array_merge to array_merge_recursive and got the same results (array keys renumbered). Merging arrays recursively some problem about existing keys, so that i wrote the function above like this: Sometimes you need to modify an array with another one here is my approach to replace an array's content recursively with delete opiton. Hi all, I have taken from net MVC tutorial, but it is in German language. array and not re-indexing, use the It returns the resulting array. The function behaves differently with numbers more than PHP_INT_MAX. This function tends to reindex arrays, which is not  mentioned in the function description. You can use the PHP array_merge() function to merge the elements or values of Note: If the input arrays contain the same string keys, then the later value for PHP - Multidimensional Arrays. The array_merge() function used to merge one or more arrays. If the input arrays have the same string keys, then the values for I would merge 2 arrays but keep the values unique in the result array. php Show comments meta to wp-admin/edit.php I’m trying to add new comment meta fieldsVia plugins/via a lot of great code examples here - it doesn't matter - they are all work great PHP array_merge_recursive() Function, You need to use array_merge_recursive instead of array_merge . In a piece of software, I … PHP is a server-side scripting language designed primarily for web development. // result: Array ( [name] => Metehan [surname] => Arslan [age] => 28 [favs] => Array ( [language] => js [planet] => mercury [city] => shanghai ) ), Array merge will return null if any parameter not an array. Moreover nested object properties aren’t merged — the last value specified in the merge replaces the last, even when there are other properties that should exist. PHP - Multidimensional Arrays. Anyway, here is what I did: In both PHP 4 and 5, array_merge preserves references in array values. This emulates replace of $_REQUEST according to variable_order=GPC. The presence of NULLs; here is an example of the issue and a fix. Of course there can only be one key equal to 'c' in the array, but the associated value will be I've changes array_merge to array_merge_recursive and got the same results (array keys renumbered). array_merge_recursive — Merge one or more arrays recursively. I had to match the array structure returned from the PHP function calling the DB and got bit. 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 We noticed array_merge is relatively slower than manually extending an array: array_merge will merge numeric keys in array iteration order, not in increasing numeric order. Here's my function to recursively merge two arrays with overwrites. If you need to preserve the numeric keys, then using + will do that. Needed an quick array_merge clone that preserves the keys: Reiterating the notes about casting to arrays, be sure to cast if one of the arrays might be null: I constantly forget the direction of array_merge so this is partially for me and partially for people like me. PHP supports multidimensional arrays that are two, three, four, five, or more levels deep. An array of values resulted from merging the arguments together. Please be aware that under circumstances where you have. We use this function to merge multiple elements or values all together into a single array which occurs in such a way that the values of one array are appended to the previous array. if you generate form select from an array, you probably want to keep your array keys and order intact. + array union operator: The keys from the first array will be preserved. it’s giving output like this. first array while not overwriting the elements from the first This recursive array merge function doesn't renumber integer keys and appends new values to existing ones OR adds a new [key => value] pair if the pair doesn't exist. « back — written by Brent on October 24, 2018 array_merge or + in PHP. The array_merge_recursive() function in PHP merges the elements of one or arrays together and returns the resulting array. PHP array_merge_recursive() Function, You need to use array_merge_recursive instead of array_merge . Static functions of Classes  with Namespace are callables too. these keys are merged together into an array, and this is done to get unique value from multi dimensional array use this instead of array_unique(), because array_unique() does not work on multidimensional: I keep seeing posts for people looking for a function to replace numeric keys. Formerly, at least one parameter has been required. The merging is occurring in such a way that the values of one array are appended to the end of the previous array. If you desire correct and performant behaviour (in contrast to the other postings) use this code. one or more arrays together so that the values of one are appended Note that if you put a number as a key in an array, it is eventually converted to an int even if you cast it to a string or put it in quotes. appended. value will not overwrite the original value, but will be appended. You can use array_merge or the + operator. If called without any arguments, returns an empty array. In above output you can see there are many duplicate entries But we want to remove these duplicate entries before merging both array. This is not that. I've tried these array_merge_recursive functions without much success. The PHP array_combine function creates a new array from two arrays that you pass as arguments to it. javascript by Batman on Jun 12 2020 Donate array_merge_recursive() fügt die Elemente von einem oder mehreren Arrays zusammen, so dass die Werte eines Arrays an die des voherigen angehängt werden. // result: Array ( [name] => Metehan [surname] => Arslan [age] => 28 [favs] => Array ( [language] => js [planet] => mercury [city] => shanghai ) ), // First array is used as the base, everything else overwrites on it, // Numeric keyed values are added (unless already there). For example: This function merges any number of arrays and maintains the keys: public function mergeArrays($arrays, $field). array_combine. Don't forget that numeric keys will be renumbered! // We set up an array with just the children, // We merge each child with its respective parent. Human Language and Character Encoding Support, https://wiki.php.net/rfc/spread_operator_for_array#advantages_over_array_merge, http://sdtuts.com/php-array_merge-function-issue/. // ensure keys are numeric values to avoid overwritting when array_merge gets called, // output: array(0 => 'a', 1 => 'b', 2 => 'c'), // output: array('k1' => 'b', 'k3' => 'c') // first 'k1' value gets overwritten by nested 'k1' value. array. I saw a lot of functions submitted that were just trying to recreate array_replace_recursive. Formerly, at least one parameter has been required. It works as documented above. array_merge_recursive () merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. that key will overwrite the previous one. I ran into a fairly unique situation where array_merge_recursive ALMOST did what I wanted, but NOT QUITE. As PHP 5.6 you can use array_merge + "splat" operator to reduce a bidimensonal array to a simple array: Sometimes we need to traverse an array and group / merge the indexes so that it is easier to extract them so that they are related in the iteration. First level of array behave as classic array_merge. The documentation is a touch misleading when it says: "If only one array is given and the array is numerically indexed, the keys get reindexed in a continuous way." array_merge is a non-referential non-inplace right-reduction. This function is used to merge the array_merge_recursive() merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. So here's what I put in the bug #73576: When mixing string keys and numeric keys, numeric keys are still renumbered after merge. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. too. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. A Computer Science portal for geeks. If called without any arguments, returns an empty array. array_merge is the equivalent of concat in other languages. /* Please note that, the array_merge() function replaces the first key by the second key if both arrays contain the same key. I needed a function similar to ian at fuzzygroove's array_interlace, but I need to pass more than two arrays. Topic: PHP / MySQL Prev|Next Answer: Use the PHP array_merge() function. Das daraus resultierende Array wird zurückgegeben. This function is used to merge the elements or values of two or more arrays together into a single array. The merging occurs in such a manner that the values of one array are appended at the end of the previous array. However, arrays more than three levels deep are hard to manage for most people. WARNING: numeric subindexes are lost when merging arrays. I recently shared how you can merge object properties with the spread operator but this method has one big limitation: the spread operator merge isn’t a “deep” merge, meaning merges are recursive. Anyways, my function hasn't been tested extensively, but it's a simple function, so in hopes that this might be useful to someone else I'm sharing. This function is similar to PHP's array_merge_recursive () function, but it handles non-array values differently. An addition to what Julian Egelstaff above wrote - the array union operation (+) is not doing an array_unique - it will just not use the keys that are already defined in the left array. ', // the first array is in the output set in every case, // integer or string as integer key - append, // if $ret[$key] is not an array you try to merge an scalar value with an array - the result is not defined (incompatible arrays). This function can now be called without any parameter. be ignored. Falls die angegebenen Arrays die selben String-Schlüssel haben, so werden die Werte dieser Schlüssel in einem Array zusammengeführt. recursively, so that if one of the values is an array itself, the Sometimes you need to modify an array with another one here is my approach to replace an array's content recursively with delete opiton. I refactored the Daniel's function and I got it: I little bit improved daniel's and gabriel's contribution to behave more like original array_merge function to append numeric keys instead of overwriting them and added usefull option of specifying which elements to merge as you more often than not need to merge only specific part of array tree, and some parts of array just need  to let overwrite previous. Values in the input arrays with numeric keys will be renumbered with to merge arrays and preserve the key i found the following working with php 4.3.1: I got tripped up for a few days when I tried to merge a (previously serialized) array into a object. ex: $a = array_merge(['k' => 'a'], ['k' => 'b']) => ['k' => 'b'] array_merge(['z' => 1], $a) => does not modify $a but returns ['k' => 'b', 'z' => 1]; Thought someone else might find it usefull. As with all things, its usually easier to write your own, which I did and it seems to work just the way I wanted. If the input arrays have the same string keys, then the values for these keys are merged together into an array, and this is done recursively, so that if one of the values is an array itself, the function will merge it with a corresponding entry in another array … This function can now be called without any parameter. An updated version of  array_merge_recursive without overwriting numeric keys from martyniuk : Human Language and Character Encoding Support, http://www.php.net/manual/hu/function.array-merge-recursive.php. It returns the resulting If you need to merge two arrays without having multiple entries, try this: As has already been noted before, reindexing arrays is most cleanly performed by the array_values() function. What is a purpose? Even with two arrays, the resulting array is re-indexed: We no longer need array_merge() as of PHP 7.4. It is mostly used by a newly coders for its user friendly environment. I read through all of the comments, and I didn't find anything that really helped me. If the value is an array, its elements will be merged/overwritten: An alternative solution where this function does not produce the desired output: Pass a custom recursive function to array_reduce(): Sharing my code to reserve the numeric keys: walfs version is pretty good, but it always assumes we want numeric keys as numeric keys. If a value in the left one is an array and also an array in the right one, the function calls itself (recursion). You can use the PHP array_merge() function to merge the elements or values of two or more arrays together into a single array. Using PHP, you can let your user directly interact with the script and easily to learned its syntax. How to merge two or more arrays into one array in PHP. For asteddy at tin dot it and others who are trying to merge arrays and keep the keys, don't forget the simple + operator. A Computer Science portal for geeks. There are possibilities where a numeric key is actually a string '123', // croak on not enough arguemnts (we need at least two), // if last is not array, then assume it is trigger for key is always string, // check that arrays count is at least two, else we don't have enough. incrementing keys starting from zero in the result array. For different ctrl-f typers, it's reduce-right, side-effect free, idempotent, and non in-place. function drupal_array_merge_deep Merges multiple arrays, recursively, and returns the merged array. In some situations, the union operator ( + ) might be more useful to you than array_merge. PHP : array_merge() function, The array_merge() is a builtin function in PHP and is used to merge two or more arrays into a single array. Note that if you want to append one array to another, using a foreach in conjuction with array_push is A LOT faster: foreach loop is faster than array_merge to append values to an existing array, so choose the loop instead if you want to add an array to the end of another. Documentation array_mergeMerge one or more arrays (PHP 4, PHP 5) array array_merge ( array array1 [, array array2 [, array ...]] ) array_merge() merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. For example: i did a small benchmark (on  PHP 5.3.3) comparing: Suffice to add, array_merge() creates a new array from the supplied array(s) and does not modify the supplied array(s). I've edit this version even a little bit more, so that the function does not override any values, but inserts them at a free key in the array: In this version the values are overwritten only if they are not an array. The difference between union and merge can be seen in an example like this: # array ( 'one' => 'one', 'two' => 'two', 'zero' => 'zero', ), # array ( 'one' => 'three', 'two' => 'four', 'zero' => 'zero', ). A multidimensional array is an array containing one or more arrays. PHP has several ways of combining two arrays into one. If the left one is an array and the right one exists but is not an array, then the right non-array-value will be used. We cover the array_combine and array_merge functions, and the array union operator. I think this version is most similar, takes more than 2 arguments and can be renamed in one place: Here is a fairly simple function that replaces while recursing. On this page we describe and demonstrate how to combine or merge two or more arrays in PHP and return a single array containing the result. The array_walk call fixed this for me. By specifying helper element mergeWithParent=true, that section of array  will be merged, otherwise latter array part will override former. to the end of the previous one. The merging is occurring in such Tip: The difference between this function and the array_merge_recursive() function is when two or more array elements have the same key. I discovered this when migrating from an Oracle DB to a MySQL DB. contain numeric keys, the later value will not overwrite the original value, but will be Nice for merging configurations. If an array key I tried to submit a bug that array_concat should be created as an alias to this but it was rejected on the basis they didn't want to polute the namespace and that the documentation should be updated instead. You can use PHP array_merge function for merging both arrays into one array. In PHP, array_merge is a builtin function that is used to merge one or more arrays into a single array. // also array_merge_recursive returns nothing in this case, ' is not an array - trying to merge array with scalar! Needed some way to fuse two arrays together and found a function here (below from thomas) and decided to update it even further to be a little more smart. Merges the elements of one or more arrays together so that the values of If, however, the arrays have the same numeric key, the later So I wrote the below function, which merges two arrays, and returns the resulting array. A multidimensional array is an array containing one or more arrays. In that case ('3') is consider as numeric and generating new numeric key instead of replacing by second one to first one. be used and the matching key's element from the second array will If, however, the arrays The base array is the left one ($a1), and if a key is set in both arrays, the right value has precedence. A small improvement upon the previously posted array_merge_recursive_distinct functions (based on daniel's version). Returning null! Here i used "::delete::" as reserved word to delete items. This implementation preserves the parameter input from the original, you can pass an infinite amount of array's to merge. There's a subtle difference between these two methods though, a difference worth knowing. Php merge array values with same keys. PHP array_merge() Function, You can use the PHP array_merge() function to merge the elements or values of two or more arrays together into a single array. In this tutorial we will create a Simple Array Merge using PHP. //  this function merges an array with the $_SESSION. The array_merge() is a builtin function in PHP and is used to merge two or more arrays into a single array. If what you want is merge all values of your array that are arrays themselves to get a resulting array of depth one, then you're more looking for array_flatten function. Maybe it's just me but they don't seem to actually go more than one level deep? PHP supports multidimensional arrays that are two, three, four, five, or more levels deep. Can anyone explain it me why there were joined two superglobal? If the input arrays have the same string keys, then the later value for There are a lot of examples here for recursion that are meant to behave more like array_merge() but they don't get it quite right or are fairly customised. Here i used "::delete::" as reserved word to delete items.