array_merge
(PHP 4, PHP 5, PHP 7, PHP 8)
array_merge — Merge one or more arrays
Description
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.
Examples
Example #1 array_merge() example
<?php
$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
print_r($result);
?>
The above example will output:
Array
(
[color] => green
[0] => 2
[1] => 4
[2] => a
[3] => b
[shape] => trapezoid
[4] => 4
)
Example #2 Simple array_merge() example
<?php
$array1 = array();
$array2 = array(1 => "data");
$result = array_merge($array1, $array2);
print_r($result);
?>
Don't forget that numeric keys will be renumbered!
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:
<?php
$array1 = array(0 => 'zero_a', 2 => 'two_a', 3 => 'three_a');
$array2 = array(1 => 'one_b', 3 => 'three_b', 4 => 'four_b');
$result = $array1 + $array2;
var_dump($result);
?>
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(5) {
[0]=>
string(6) "zero_a"
[2]=>
string(5) "two_a"
[3]=>
string(7) "three_a"
[1]=>
string(5) "one_b"
[4]=>
string(6) "four_b"
}
Example #3 array_merge() with non-array types
<?php
$beginning = 'foo';
$end = array(1 => 'bar');
$result = array_merge((array) $beginning, (array) $end);
print_r($result);
?>
The above example will output:
Array
(
[0] => foo
[1] => bar
)
