PHP Exercises: Retrieve all of the values for a given key

PHP: Exercise-87 with Solution

Write a PHP program to retrieve all of the values for a given key.

Sample Solution:

PHP Code:

<?php
// Function definition for 'pluck' that takes an array of items and a key as parameters
function pluck($items, $key)
{
    // Use 'array_map' to apply a callback function to each element of the array
    return array_map( function($item) use ($key) {
        // Check if the item is an object, and if so, access the property specified by the key
        // If the item is an array, access the array element specified by the key
        return is_object($item) ? $item->$key : $item[$key];
    }, $items);
}

// Call 'pluck' with an array of associative arrays and a key, then display the result using 'print_r'
print_r(pluck([
    ['product_id' => 'p100', 'name' => 'Computer'],
    ['product_id' => 'p200', 'name' => 'Laptop'],
], 'name'));

?>

Explanation:

• Function Definition:
• The function pluck is defined to take two parameters:
• $items: an array of items (either associative arrays or objects).
• $key: a string representing the key or property to extract from each item.
• Using array_map:
• Inside the function, array_map is utilized to iterate over each element in the $items array.
• A callback function is defined within array_map.
• Extracting Values:
• The callback function checks if the current item is an object:
• If it is an object, it accesses the property specified by $key (e.g., $item->$key).
• If it is an array, it accesses the array element specified by $key (e.g., $item[$key]).
• Return Statement:
• The modified array containing only the values associated with the specified key is returned.
• Example Usage:
• The pluck function is called with an array of associative arrays and the key 'name':
• It extracts the names of the products from the input array.
• The result is displayed using print_r.
• Purpose:
• The pluck function is useful for extracting a specific property or value from an array of objects or associative arrays, effectively creating a new array containing only those values.

Output:

Array
(
    [0] => Computer
    [1] => Laptop
)

Flowchart:

PHP Code Editor:

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