PHP Exercises: Get the last element for which the given function returns a truth value

Last update on April 19 2025 11:50:21 (UTC/GMT +8 hours)

81. Get Last Element Matching a Condition

Write a PHP program to get the last element for which the given function returns a truth value.

Sample Solution:

PHP Code:

<?php
// Function definition for 'find_Last' that takes an array of items and a filtering function as parameters
function find_Last($items, $func)
{
    // Use 'array_filter' to filter the items based on the given function
    $filteredItems = array_filter($items, $func);

    // Use 'array_pop' to retrieve and return the last element from the filtered array
    return array_pop($filteredItems);
}

// Call 'find_Last' with an array and an anonymous function checking for odd numbers, then display the result using 'echo'
echo find_Last([1, 2, 3, 4], function ($n) {
    return ($n % 2) === 1;
});

// Display a newline
echo "\n";

// Call 'find_Last' with an array and an anonymous function checking for even numbers, then display the result using 'echo'
echo find_Last([1, 2, 3, 4], function ($n) {
    return ($n % 2) === 0;
});

?>

Explanation:

Define find_Last Function:

The function find_Last accepts:

$items: an array of items to search through.
$func: a custom function used to filter the items.

Filter Array Using Custom Function:

array_filter($items, $func): Filters $items according to $func, resulting in an array of items that meet the function’s condition (e.g., odd or even numbers).

Return the Last Matching Item:

array_pop($filteredItems): Retrieves and returns the last element in filteredItems, which is the last item in $items that met the condition specified by $func.

Function Calls and Output:

find_Last([1, 2, 3, 4], function ($n) { return ($n % 2) === 1; }):

Filters for odd numbers, returns 3, the last odd number.

find_Last([1, 2, 3, 4], function ($n) { return ($n % 2) === 0; }):

Filters for even numbers, returns 4, the last even number.

Purpose:

The function find_Last finds and returns the last element in an array that meets a specified condition, offering a flexible way to retrieve elements based on custom criteria.

Output:

3
4

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to traverse an array from end to start and return the last element for which a given callback returns true.
Write a PHP script to reverse iterate over a collection and output the last matching element based on a condition.
Write a PHP function to identify the final element in an array that meets a specified criterion.
Write a PHP script to find and return the last truthy element in an array using a custom search function.

PHP Code Editor:

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