Custom Implementation of array_slice Without PHP Built-in Functions

Description

This example shows how to implement the functionality of array_slice manually without using PHP built-in functions. The array_slice function extracts a portion of an array based on the starting index and the length specified. Below, we achieve this using a custom function.

Code Example:

<?php
// Function to mimic array_slice functionality
function customArraySlice($array, $start, $length = null) {
    $slicedArray = [];
    $arrayLength = count($array);
    
    // Adjust negative start index
    if ($start < 0) {
        $start = $arrayLength + $start;
    }

    // Handle no length (slice till the end)
    if ($length === null) {
        $length = $arrayLength - $start;
    }

    // Build the sliced array
    for ($i = $start; $i < $start + $length && $i < $arrayLength; $i++) {
        $slicedArray[] = $array[$i];
    }

    return $slicedArray;
}

// Test array
$fruits = ["apple", "banana", "cherry", "date", "elderberry"];

// Call the custom function
$result = customArraySlice($fruits, 1, 3);

// Output
echo "Sliced Array: ";
print_r($result);
?>

Output:

Sliced Array: Array
(
    [0] => banana
    [1] => cherry
    [2] => date
)

  This manual approach replicates the functionality of array_slice.

  It handles both positive and negative starting indices.

  The function also works without specifying the length, extracting elements until the end of the array.

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