PHP: Insert an element with the specified key at the beginning of the array
Issue
With array_unshift(), we can prepend one or more elements to the beginning of an array. All numerical array keys will be modified to start counting from zero while literal keys won't be changed.
$arr = [
"key2" => 2,
"3" => 3
];
array_unshift($arr, 1, 100);
print_r($arr);Output:
Array
(
[0] => 1
[1] => 100
[key2] => 2
[2] => 3
)It is not possible to add an element with the specified key at the front of the array using array_unshift() or array_marge().
Solution
The + operator won't reindex the keys in array. For example.
$arr = [
"key2" => 2,
"3" => 3
];
$arr = [1 => 1, 100 => 100] + $arr;
print_r($arr);Output:
Array
(
[1] => 1
[100] => 100
[key2] => 2
[3] => 3
)