PHP Exercises: Mutate the original array to filter out the values specified

Last update on April 19 2025 11:50:18 (UTC/GMT +8 hours)

88. Mutate Array to Filter Out Specified Values

Write a PHP program to mutate the original array to filter out the values specified.

Sample Solution:

PHP Code:

<?php
// Licence: https://bit.ly/2CFA5XY

// Function definition for 'pull' that takes an array reference and variable number of parameters as input
function pull(&$items, ...$params)
{
    // Use 'array_diff' to remove elements specified by the parameters from the array
    // Use 'array_values' to reindex the array after removal
    $items = array_values(array_diff($items, $params));

    // Return the modified array
    return $items;
}

// Initialize an array '$items' with repeated values
$items = ['a', 'b', 'c', 'a', 'b', 'c'];

// Call 'pull' with the array and specified values to be removed, then display the result using 'print_r'
print_r(pull($items, 'a', 'c'));

?>

Explanation:

Function Definition:

The function pull is defined to take two parameters:

&$items: an array passed by reference, allowing modifications directly to the original array.
...$params: a variable number of additional parameters representing the values to be removed from the array.

Removing Elements:

Inside the function:

array_diff($items, $params) is used to create a new array that contains all elements of $items except those that match any of the values specified in $params.
array_values() is applied to reindex the resulting array after the removal of specified elements, ensuring that the keys are reset.

Updating the Original Array:

The modified array (after removal of specified elements) is assigned back to $items, effectively updating the original array.

Return Statement:

The modified array is returned from the function.

Example Initialization:

An array $items is initialized with repeated values: ['a', 'b', 'c', 'a', 'b', 'c'].

Function Call:

The pull function is called with $items and the values 'a' and 'c' specified for removal.

Displaying Results:

The result of the pull function call is displayed using print_r, showing the updated array after removing the specified values.

Purpose:

The pull function effectively filters out specified values from an array, modifying the original array in place and returning the updated array.

Output:

Array
(
    [0] => b
    [1] => b
)

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to remove specified values from an array in place without using built-in filtering functions.
Write a PHP function to iterate through an array and unset elements that match a provided blacklist.
Write a PHP script to modify an original array by filtering out unwanted values using a custom loop.
Write a PHP script to mutate an array to eliminate all occurrences of certain specified items.

PHP Code Editor:

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