Merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.
If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will
not
overwrite the original value, but will be appended.
Values in the input arrays with numeric keys will be renumbered with incrementing keys starting from zero in the result array.
Parameters
arrays
Variable list of arrays to merge.
Return Values
Returns the resulting array. If called without any arguments, returns an empty
array
.
Changelog
Version
Description
7.4.0
This function can now be called without any parameter. Formerly, at least one parameter has been required.
Don't forget that numeric keys will be renumbered!
Array
(
[0] => data
)
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:
The keys from the first array will be preserved. If an array key exists in both arrays, then the element from the first array will be used and the matching key's element from the second array will be ignored.
array_merge_recursive() - Merge one or more arrays recursively
array_replace() - Replaces elements from passed arrays into the first array
array_combine() - Creates an array by using one array for keys and another for its values
array operators
PHP / array_merge_recursive — DevDocs
array_merge_recursive
(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
array_merge_recursive
—
Merge one or more arrays recursively
Description
array_merge_recursive(array...$arrays):array
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. It returns the resulting array.
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 too. If, however, the arrays have the same numeric key, the later value will not overwrite the original value, but will be appended.
Parameters
arrays
Variable list of arrays to recursively merge.
Return Values
An array of values resulted from merging the arguments together. If called without any arguments, returns an empty
array
.
Changelog
Version
Description
7.4.0
This function can now be called without any parameter. Formerly, at least one parameter has been required.
SORT_LOCALE_STRING
- compare items as strings, based on the current locale. It uses the locale, which can be changed using
setlocale()
SORT_NATURAL
- compare items as strings using "natural ordering" like
natsort()
SORT_FLAG_CASE
- can be combined (bitwise OR) with
SORT_STRING
or
SORT_NATURAL
to sort strings case-insensitively
This argument can be swapped with
array1_sort_order
or omitted entirely, in which case
SORT_REGULAR
is assumed.
rest
More arrays, optionally followed by sort order and flags. Only elements corresponding to equivalent elements in previous arrays are compared. In other words, the sort is lexicographical.
In this example, after sorting, the first array will contain 0, 10, 100, 100. The second array will contain 4, 1, 2, 3. The entries in the second array corresponding to the identical entries in the first array (100 and 100) were sorted as well.
In this example, after sorting, the first array will transform to "10", 100, 100, 11, "a" (it was sorted as strings in ascending order). The second will contain 1, 3, "2", 2, 1 (sorted as numbers, in descending order).
In this example, we will order by
volume
descending,
edition
ascending.
We have an array of rows, but
array_multisort()
requires an array of columns, so we use the below code to obtain the columns, then perform the sorting.
<?php// Obtain a list of columnsforeach($dataas$key=>$row){$volume[$key]=$row['volume'];$edition[$key]=$row['edition'];}// you can use array_column() instead of the above code$volume=array_column($data,'volume');$edition=array_column($data,'edition');// Sort the data with volume descending, edition ascending// Add $data as the last parameter, to sort by the common keyarray_multisort($volume,SORT_DESC,$edition,SORT_ASC,$data);?>
The dataset is now sorted, and will look like this:
Both
SORT_STRING
and
SORT_REGULAR
are case sensitive, strings starting with a capital letter will come before strings starting with a lowercase letter.
To perform a case insensitive sort, force the sorting order to be determined by a lowercase copy of the original array.
array_pad()
returns a copy of the
array
padded to size specified by
length
with value
value
. If
length
is positive then the array is padded on the right, if it's negative then on the left. If the absolute value of
length
is less than or equal to the length of the
array
then no padding takes place. It is possible to add at most 1048576 elements at a time.
Parameters
array
Initial array of values to pad.
length
New size of the array.
value
Value to pad if
array
is less than
length
.
Return Values
Returns a copy of the
array
padded to size specified by
length
with value
value
. If
length
is positive then the array is padded on the right, if it's negative then on the left. If the absolute value of
length
is less than or equal to the length of the
array
then no padding takes place.
Examples
Example #1
array_pad()
example
<?php$input=array(12,10,9);$result=array_pad($input,5,0);// result is array(12, 10, 9, 0, 0)$result=array_pad($input,-7,-1);// result is array(-1, -1, -1, -1, 12, 10, 9)$result=array_pad($input,2,"noop");// not padded?>
See Also
array_fill() - Fill an array with values
range() - Create an array containing a range of elements