PHP array slicing uses index as key name

When using PHP array slicing, you can use the preserve_keys parameter to retain the original key names. Syntax: array_slice($array, $offset, $length, TRUE). This way, the key names of the elements in the slice result will be the same as in the original array.

PHP array slicing using index as key

Array slicing in PHP is a useful tool for extracting parts of an array. However, by default, the element keys in the slicing result are reordered, starting from 0. This may be inconvenient in some cases, especially when you want to use an index as the key name.

To use the index as the key name, you can use the preserve_keys parameter of the array_slice() function. This parameter is a Boolean value and defaults to FALSE. Setting this parameter to TRUE will preserve the original key names in the sliced ​​result.

Syntax:

array_slice($array, $offset, $length, $preserve_keys)

Where:

• $array - The array to be sliced
• $offset - The starting index of slicing
• $length - The number of elements to slice (optional, defaults to the end of the array)
• $preserve_keys - Preserves the Boolean value of the original key name

Practical example:

Consider the following array:

$colors = [
    'red' => '#ff0000',
    'green' => '#00ff00',
    'blue' => '#0000ff',
];

To extract the elements at index 1 and 2 from the array while retaining the index as the key, you can use the following code:

$sliced_colors = array_slice($colors, 1, 2, TRUE);

print_r($sliced_colors);

Output:

Array
(
    [1] => #00ff00
    [2] => #0000ff
)

In this example, The $sliced_colors array contains elements from index 1 to 2 (exclusive), their keys remain unchanged.

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