Usage examples of PHP high-order data structures

PHP Examples of usage of high-order data structures: Array: Stores an ordered collection of key-value pairs; List: Stores an ordered collection of numeric key data; Set: Stores a collection of unique values, unordered; Heap: Priority queue, elements are prioritized Level sorting; Hash table: A collection of key-value pairs to quickly find key values. Practical case: User database, using arrays to store user data, and processing data through array functions, such as finding John Doe's email address.

Usage examples of PHP high-order data structures

Introduction

PHP High First-order data structures provide a flexible and efficient way to organize and process large amounts of data. They allow developers to create complex data structures that are capable of storing and processing data in more advanced ways.

Array

Array is the most basic higher-order data structure in PHP. They are an ordered collection of key-value pairs in which different types of data can be stored.

$arr = [
    'name' => 'John Doe',
    'age' => 30,
    'address' => '123 Main Street'
];

List

A list is similar to an array, but the keys are numbers instead of strings. They are used to store ordered collections of data.

$list = [
    'apple',
    'orange',
    'banana'
];

Collection

A collection is an unordered data structure in which each element appears only once. They are used to store unique values ​​such as IDs or names.

$set = new SplObjectStorage();
$set->attach($obj1);
$set->attach($obj2);

Heap

A heap is a priority queue in which elements are ordered by their priority. They are used to get data from large to small or small to large.

$heap = new SplPriorityQueue();
$heap->insert('item1', 10);
$heap->insert('item2', 5);
$heap->insert('item3', 15);

Hash table

A hash table is a collection of key-value pairs where the keys can be looked up quickly. They are used to store and retrieve data efficiently.

$hashtable = new SplArrayObject();
$hashtable['key1'] = 'value1';
$hashtable['key2'] = 'value2';

Practical case

The following is a practical case using high-order data structures:

User database

Consider a user database where each user consists of an ID, name, and email address. We can use a PHP array to store this data:

$users = [
    [
        'id' => 1,
        'name' => 'John Doe',
        'email' => 'john.doe@example.com'
    ],
    [
        'id' => 2,
        'name' => 'Jane Smith',
        'email' => 'jane.smith@example.com'
    ]
];

We can then use array functions (such as array_map() and array_filter()) to process the data . For example, we can find John Doe's email address:

$email = array_map(function($user) {
    return $user['email'];
}, array_filter($users, function($user) {
    return $user['name'] === 'John Doe';
}))[0];

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