How can I extract the first N elements of an array in PHP while preserving their original indices?

How to Retrieve the First N Elements of an Array

When working with arrays, it's often necessary to extract a subset of elements based on their position. The best method for achieving this in PHP is through the array_slice() function.

Using array_slice()

To use array_slice(), provide the following parameters:

• $input (array): The original array to extract elements from.
• $offset (integer): The starting index from which to retrieve elements.
• $length (integer): The number of elements to retrieve.

For example, to extract the first three elements of an array:

<code class="php">$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 0, 3);   // returns "a", "b", and "c"</code>

Managing Array Indices

However, it's important to note that array_slice() resets the numeric indices in the output array by default. If you want to preserve the original indices, use the preserve_keys flag set to true:

<code class="php">$output = array_slice($input, 2, 3, true);</code>

Output:

array([3]=>'c', [4]=>'d', [5]=>'e');

By setting preserve_keys to true, the output array maintains the original indices from the input array.

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