Given an Array, the task is to remove the first element from the array in PHP. There are three methods to remove the first element from an array, these are – using array_shift(), array_slice(), and unset() functions. Let’s explore each method with detailed explanations and code examples.

Approach 1: Using array_shift() Function

The array_shift() function removes the first element from an array and returns it. This function modifies the original array.

<?php
    $arr = array(10, 20, 30, 40, 50, 60);
    $removedElement = array_shift($arr);
    echo "Removed element: " . $removedElement . "\n";
    echo "Updated array: ";
    print_r($arr);

?>

Removed element: 10
Updated array: Array
(
    [0] => 20
    [1] => 30
    [2] => 40
    [3] => 50
    [4] => 60
)

Approach 2: Using array_slice() Function

The array_slice() function is used to extract a slice of an array. By specifying the start index as 1, you can remove the first element from the array.

<?php
    $arr = array(10, 20, 30, 40, 50, 60);
    $updated_array = array_slice($arr, 1);
    echo "Updated array: ";
    print_r($updated_array);

?>

Updated array: Array
(
    [0] => 20
    [1] => 30
    [2] => 40
    [3] => 50
    [4] => 60
)

Approach 3: Using unset() Function

You can also use the unset() function to remove the first element from an array. This function takes the array and the index of the element to be removed as arguments.

<?php
    $arr = array(10, 20, 30, 40, 50, 60);
    unset($fruits[0]);
    echo "Updated array: ";
    print_r($arr);

?>

Updated array: Array
(
    [0] => 10
    [1] => 20
    [2] => 30
    [3] => 40
    [4] => 50
    [5] => 60
)

Approach 4: Using array_splice() Function

The array_splice() function can be used to remove elements from an array and optionally replace them with other elements.

<?php
    $arr = [1, 2, 3, 4, 5];
    array_splice($arr, 0, 1);
    print_r($arr);

?>

Array
(
    [0] => 2
    [1] => 3
    [2] => 4
    [3] => 5
)

Approach 5: Using the array_diff_key() Function

This method involves using the array_diff_key() function to remove the first element from an array by comparing keys. The array_diff_key() function compares the keys of two arrays and returns the differences. This approach is beneficial when you want to remove the first element based on its key, especially in associative arrays where keys are not necessarily numeric.

Example: Here’s how you can use array_diff_key() to remove the first element from both numeric and associative arrays. First, identify the key of the first element, then create a temporary array with this key and use array_diff_key() to remove it.

<?php
$array = ['a' => 'apple', 'b' => 'banana', 'c' => 'cherry'];

// Getting the first key of the array
$firstKey = array_key_first($array);

// Removing the first element
$modifiedArray = array_diff_key($array, [$firstKey => ""]);

print_r($modifiedArray);

?>

Array
(
    [b] => banana
     => cherry
)

Approach 6: 5. Using a Loop

In this approach we will shifting the all elements of the array to the left using a loop and then remove the last element.

<?php
$array = ['g', 'e', 'e', 'k'];

for ($i = 0; $i < count($array) - 1; $i++) {
    $array[$i] = $array[$i + 1];
}
unset($array[count($array) - 1]);
print_r($array);
?>

Array
(
    [0] => e
    [1] => e
    [2] => k
)